FEBS Letters RSS feed: Articles in Press. FEBS Letters is one of the world's leading journals in biochemistry and is renowned both for its quality of content and speed of production. Bringing together the most important developments in the molecular biosciences, FEBS Letters provides an international forum for Minireviews, hypotheses and research letters that merit urgent publication. FEBS Letters offers: • Faster publication: ? Accepted articles are published online in 3 days ? The print version of the article is published in 3 to 5 weeks after acceptance • Full-text article disclosure in HTML and PDF formats • Articles in Press are included in PubMed • Easy online manuscript submission system • Transparent online peer review and manuscript tracking system • No page charges • Free color figures Subject Coverage: The subject area of FEBS Letters is broad. It covers biochemistry (including protein chemistry, enzymology, nucleic acid chemistry, metabolism, and immunochemistry), structural biology, biophysics, computational biology (genomics, proteomics, bioinformatics), molecular genetics, molecular biology and molecular cell biology (signal transduction, intracellular traffic, regulation of cellular proliferation, cell-cell interactions) and systems biology. Studies on microbes, plants and animals at the molecular level are within the scope of FEBS Letters. Submitting Authors: Manuscripts can be submitted to FEBS Letters at: http://ees.elsevier.com/febsletters/ http://www.febsletters.org//inpress?rss=yesElsevier Inc.en © 2010 Published by Elsevier Inc. FEBS Letters0014-57932010-03-11 © 2010 Published by Elsevier Inc. healthpermissions@elsevier.comhttp://www.febsletters.org/article/PIIS0014579310002073/abstract?rss=yesAbstract: Plasma membrane channels have been extensively studied, and their physiological roles are well established. In contrast, relatively little information is available about intracellular ion channels. ChLoride Intracellular Channel (CLICs) proteins are a novel class of putative intracellular ion channels. They are widely expressed in different intracellular compartments, and possess distinct properties such as the presence of a single transmembrane domain, and a dimorphic existence as either a soluble or membranous form. How these soluble proteins unfold, target to, and auto-insert into the intracellular membranes to form functional integral ion channels is a complex biological question. Recent information from studies of their crystal structures, biophysical characterization and functional roles has provoked interest in these unusual channels.Two decades with dimorphic ChLoride Intracellular Channels (CLICs) - Accepted ManuscriptHarpreet Singh10.1016/j.febslet.2010.03.013FEBS Letters (2010)2010-03-11FEBS Letters2010-03-11http://www.febsletters.org/article/PIIS0014579310001936/abstract?rss=yesAbstract: In the current work, we report that specific inhibition of Janus tyrosine kinase (JAK3) via NC1153 induces apoptosis of certain leukemia/lymphoma cell lines. Affymetrix microarray profiling following NC1153 treatment unveiled JAK3 dependent survival modulating pathways (p53, TGF-β, TNFR and ER stress) in Kit225 cells. IL-2 responsive NC1153 target genes were regulated in human JAK3 positive, but not in JAK3 negative lymphoid tumor cells. Moreover, primary lymphoma samples revealed that a number of these genes were reciprocally regulated during disease progression and JAK3 inhibition suggesting that downstream targets of JAK3 could be exploited in the development of novel cancer treatment regimes.Uncoupling JAK3 activation induces apoptosis in human lymphoid cancer cells via regulating critical survival pathways - Uncorrected ProofZsuzsanna S. Nagy, Jeremy A. Ross, Georgialina Rodriguez, Julia Bader, Jonathan Dimmock, Robert A. Kirken10.1016/j.febslet.2010.02.071FEBS Letters (2010)2010-03-10FEBS Letters2010-03-10http://www.febsletters.org/article/PIIS0014579310001948/abstract?rss=yesAbstract: Quiescin sulfhydryl oxidase (QSOX) catalyzes formation of disulfide bonds between cysteine residues in substrate proteins. Human QSOX1 is a multi-domain, monomeric enzyme containing a module related to the single-domain sulfhydryl oxidases of the Erv family. A partial QSOX1 crystal structure reveals a single-chain pseudo-dimer mimicking the quaternary structure of Erv enzymes. However, one pseudo-dimer “subunit” has lost its cofactor and catalytic activity. In QSOX evolution, a further concatenation to a member of the protein disulfide isomerase family resulted in an enzyme capable of both disulfide formation and efficient transfer to substrate proteins.QSOX contains a pseudo-dimer of functional and degenerate sulfhydryl oxidase domains - Uncorrected ProofAssaf Alon, Erin Heckler, Colin Thorpe, Deborah Fass10.1016/j.febslet.2010.03.001FEBS Letters (2010)2010-03-10FEBS Letters2010-03-10http://www.febsletters.org/article/PIIS001457931000195X/abstract?rss=yesAbstract: The redox potentials Em(QA/) of the primary quinone electron acceptor QA in oxygen-evolving photosystem II complexes of three species were determined by spectroelectrochemistry. The Em(QA/) values were experimentally found to be −162±3mV for a higher plant spinach, −171±3mV for a green alga Chlamydomonas reinhardtii and −104±4mV vs. SHE for a red alga Cyanidioschyzon merolae. On the basis of possible deviations for the experimental values, as estimated to differ by 9–29mV from each true value, plausible causes for such remarkable species-dependence of Em(QA/) are discussed, mainly by invoking the effects of extrinsic subunits on the delicate structural environment around QA.Species-dependence of the redox potential of the primary quinone electron acceptor QA in photosystem II verified by spectroelectrochemistry - Uncorrected ProofTadao Shibamoto, Yuki Kato, Ryo Nagao, Takuya Yamazaki, Tatsuya Tomo, Tadashi Watanabe10.1016/j.febslet.2010.03.002FEBS Letters (2010)2010-03-10FEBS Letters2010-03-10http://www.febsletters.org/article/PIIS0014579310001961/abstract?rss=yesAbstract: Previous studies have shown that testisin promotes malignant transformation in cancer cells. To define the mechanism of testisin-induced carcinogenesis, we performed yeast two-hybrid analysis and identified maspin, a tumor suppressor protein, as a testisin-interacting molecule. The direct interaction and cytoplasmic co-localization of testisin with maspin was confirmed by immunoprecipitation and confocal analysis, respectively. In cervical cancer cells, maspin modulated cell death and invasion; however, these effects were inhibited by testisin in parallel experiments. Of interest, the doxorubicin resistance was dramatically reduced by testisin knockdown (P=0.016). Moreover, testisin was found to be over-expressed in cervical cancer samples as compared to matched normal cervical tissues. Thus, we postulate that testisin may promote carcinogenesis by inhibiting tumor suppressor activity of maspin.Structured summary: MINT-7712215, MINT-7712176: Testisin (uniprotkb:Q9Y6M0) binds (MI:0407) to Maspin (uniprotkb:P36952) by pull down (MI:0096)MINT-7712188: Testisin (uniprotkb:Q9Y6M0) and Maspin (uniprotkb:P36952) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7712115: Testisin (uniprotkb:Q9Y6M0) physically interacts (MI:0915) with Maspin (uniprotkb:P36952) by two-hybrid (MI:0018)MINT-7712162, MINT-7712128: Maspin (uniprotkb:P36952) physically interacts (MI:0915) with Testisin (uniprotkb:Q9Y6M0) by anti bait co-immunoprecipitation (MI:0006)MINT-7712147: Testisin (uniprotkb:Q9Y6M0) physically interacts (MI:0915) with Maspin (uniprotkb:P36952) by anti tag co-immunoprecipitation (MI:0007)Interaction of testisin with maspin and its impact on invasion and cell death resistance of cervical cancer cells - Uncorrected ProofSeon-Yong Yeom, Hye-Lim Jang, Sookja Lee, Eunhee Kim, Hee Jung Son, Byoung-Gie Kim, Chaehwa Park10.1016/j.febslet.2010.02.072FEBS Letters (2010)2010-03-10FEBS Letters2010-03-10http://www.febsletters.org/article/PIIS0014579310001973/abstract?rss=yesAbstract: The virus inducible non-coding RNA (VINC) was detected initially in the brain of mice infected with Japanese encephalitis virus (JEV) and rabies virus. VINC is also known as NEAT1 or Men epsilon RNA. It is localized in the nuclear paraspeckles of several murine as well as human cell lines and is essential for paraspeckle formation. We demonstrate that VINC interacts with the paraspeckle protein, P54nrb through three different protein interaction regions (PIRs) one of which (PIR-1) is localized near the 5′ end while the other two (PIR-2, PIR-3) are localized near the 3′ region of VINC. Our studies suggest that VINC may interact with P54nrb through a novel mechanism which is different from that reported for protein coding RNAs.Identification of protein interaction regions of VINC/NEAT1/Men epsilon RNA - Uncorrected ProofU.M. Sreenivasa Murthy, Pundi N. Rangarajan10.1016/j.febslet.2010.03.003FEBS Letters (2010)2010-03-10FEBS Letters2010-03-10http://www.febsletters.org/article/PIIS0014579310002048/abstract?rss=yesAbstract: Oculopharyngeal muscular dystrophy is caused by small alanine expansions in PABPN1 protein resulting in its intranuclear accumulation in skeletal muscle. 3F5 llama antibody specifically interferes with PABPN1 aggregation process in vitro and in vivo. To understand the structural basis for its epitope recognition we mapped the binding interface of 3F5 with PABPN1 and provide a structural model of the 3F5-PABPN1 complex. We show that 3F5 Complementarity Determining Regions create a cavity in which PABPN1 α-helical domain resides by involving critical residues previously implicated in the aggregation process. These results may increase our understanding of PABPN1 aggregation mechanism and the therapeutic potential of 3F5.Structural basis for a PABPN1 aggregation-preventing antibody fragment in OPMD - Accepted ManuscriptAntonietta Impagliazzo, Armand W. Tepper, Theo C. Verrips, Marcellus Ubbink, Silvère M. van der Maarel10.1016/j.febslet.2010.03.010FEBS Letters (2010)2010-03-10FEBS Letters2010-03-10http://www.febsletters.org/article/PIIS001457931000205X/abstract?rss=yesAbstract: Triad 1 (2 RING [really interesting new gene] fingers and DRIL [double RING finger linked] 1) is an E3 ligase that induces apoptosis and clonogenic inhibition in myeloid cells through Gfi-1 stabilization. Here we demonstrate that Triad 1 induces apoptosis in several cancer cell lines including MCF7, A549, U2OS, and HCT 116 p53+/+ cells via its RING ligase activity. Interestingly, in these cancer cells, Triad 1-induced apoptosis is not mediated by Gfi-1 stabilization but is instead p53-dependent. Moreover, Triad 1 promotes transactivation of p53. These results suggest that Triad 1 can induce apoptosis through its ligase activity via p53 activation.Triad 1 induces apoptosis by p53 activation - Accepted ManuscriptJin Hyuk Jung, Sun-Mi Lee, Su-Jae Lee, In-Chul Park, Young-Woo Jin, Jae Ho Lee, Sungkwan An10.1016/j.febslet.2010.03.011FEBS Letters (2010)2010-03-10FEBS Letters2010-03-10http://www.febsletters.org/article/PIIS0014579310002061/abstract?rss=yesAbstract: This study demonstrates that in vitro incubation of isolated rat brain mitochondria with recombinant human α-synuclein leads to dose dependent loss of mitochondrial transmembrane potential and phosphorylation capacity. However, α-synuclein does not seem to have any significant effect on the activities of respiratory chain complexes under similar conditions of incubation suggesting that the former may impair mitochondrial bioenergetics by direct effect on mitochondrial membranes. Moreover, the recombinant wild type α-synuclein and different mutant forms (A30P, A53T and E46K) have essentially similar effects on rat brain isolated mitochondria. The results are significant in view of the fact that α-synucleinopathy is involved in the pathogenesis of Parkinson’s disease.α-Synuclein induced membrane depolarization and loss of phosphorylation capacity of isolated rat brain mitochondria : Implications in Parkinson’s Disease - Accepted ManuscriptKalpita Banerjee, Maitrayee Sinha, Chi Le Lan Pham, Sirsendu Jana, Dalia Chanda, Roberto Cappai, Sasanka Chakrabarti10.1016/j.febslet.2010.03.012FEBS Letters (2010)2010-03-10FEBS Letters2010-03-10http://www.febsletters.org/article/PIIS0014579310001985/abstract?rss=yesAbstract: Defensins constitute a major class of cationic antimicrobial peptides in mammals and vertebrates, acting as effectors of innate immunity against infectious microorganisms. It is generally accepted that defensins are bactericidal by disrupting the anionic microbial membrane. Here, we provide evidence that membrane activity of human α-defensins does not correlate with antibacterial killing. We further show that the α-defensin Human Neutrophil Peptide 1 (HNP-1) binds to the cell wall precursor lipid II and that reduction of lipid II levels in the bacterial membrane significantly reduces bacterial killing. The interaction between defensins and Lipid II suggests the inhibition of cell wall synthesis as a novel antibacterial mechanism of this important class of host defense peptides.Functional Interaction of Human Neutrophil Peptide-1 with the cell wall precursor Lipid II - Accepted ManuscriptErik de Leeuw, Changqing Li, Pengyun Zeng, Chong Li, Marlies Diepeveen-de Buin, Wei-Yue Lu, Eefjan Breukink, Wuyuan Lu10.1016/j.febslet.2010.03.004FEBS Letters (2010)2010-03-08FEBS Letters2010-03-08http://www.febsletters.org/article/PIIS0014579310001997/abstract?rss=yesAbstract: Ryanodine receptors (RyR) regulate intracellular Ca2+ release in many cell types and have been implicated in a number of inherited human diseases. Over the past 15years genetically engineered mouse models have been developed to elucidate the role that RyRs play in physiology and pathophysiology. To date these models have implicated RyRs in fundamental biological processes including excitation–contraction coupling and long term plasticity as well as diseases including malignant hyperthermia, cardiac arrhythmias, heart failure, and seizures. In this review we summarize the RyR mouse models and how they have enhanced our understanding of the RyR channels and their roles in cellular physiology and disease.Ryanodine receptor studies using genetically engineered mice - Uncorrected ProofAlexander Kushnir, Matthew Betzenhauser, Andrew R. Marks10.1016/j.febslet.2010.03.005FEBS Letters (2010)2010-03-08FEBS Letters2010-03-08REVIEWhttp://www.febsletters.org/article/PIIS0014579310002000/abstract?rss=yesAbstract: This work studied the role of cyclic AMP responsive element binding protein (CREB) in the up-regulation of M1 muscarinic acetylcholine receptor (M1 receptor) density by sarsasapogenin (ZMS) in CHO cells transfected with M1 receptor gene (CHOm1 cells). During cell aging, sarsasapogenin elevated M1 receptor density as well as CREB and phosphor-CREB (pCREB) levels. CREB peaked earliest, followed by pCREB and M1 receptor density peaked last. When CREB synthesis was blocked by antisense oligonucleotides, the elevation effect of sarsasapogenin on M1 receptor density was abolished. These results suggest that sarsasapogenin up-regulates M1 receptor density in aged cells by promoting CREB production and phosphorylation. Furthermore, the results support the hypothesis that pCREB regulates M1 receptor gene expression through heterodimer formation.Role of CREB in the regulatory action of sarsasapogenin on muscarinic M1 receptor density during cell aging - Uncorrected ProofHaiyan Hu, Rui Zhang, Yongfang Zhang, Zongqin Xia, Yaer Hu10.1016/j.febslet.2010.03.006FEBS Letters (2010)2010-03-08FEBS Letters2010-03-08http://www.febsletters.org/article/PIIS0014579310002012/abstract?rss=yesAbstract: The 77kDa subunit of the polyadenylation cleavage stimulation factor (CstF77) is important in messenger RNA 3′ end processing. Previously, we demonstrated that AtCstF77 interacts with AtCPSF30, the Arabidopsis ortholog of the 30kDa subunit of the Cleavage and Polyadenylation Specificity Factor. In further dissecting this interaction, it was found that the C-terminus of AtCstF77 interacts with AtCPSF30. Remarkably, we also found that the C-terminal domain of AtCstF77 possesses RNA-binding ability. These studies therefore reveal AtCstF77 to be an RNA-binding protein, adding yet another RNA-binding activity to the plant polyadenylation complex. This raises interesting questions as to the means by which RNAs are recognized during mRNA 3′ end formation in plants.Structured summary:: MINT-7712550: AtCstF77 (uniprotkb:Q8LKG5) binds (MI:0407) to AtCPSF30 (uniprotkb:A9LNK9) by pull down (MI:0096)The Arabidopsis ortholog of the 77kDa subunit of the cleavage stimulatory factor (AtCstF-77) involved in mRNA polyadenylation is an RNA-binding protein - Uncorrected ProofStephen A. Bell, Arthur G. Hunt10.1016/j.febslet.2010.03.007FEBS Letters (2010)2010-03-08FEBS Letters2010-03-08http://www.febsletters.org/article/PIIS0014579310002024/abstract?rss=yesAbstract: ARMET is an endoplasmic reticulum (ER) stress-inducible protein that is required for maintaining cell viability under ER stress conditions. However, the exact molecular mechanisms by which ARMET protects cells are unknown. Here, we have analyzed the solution structure of ARMET. ARMET has an entirely α-helical structure, which is composed of two distinct domains. Positive charges are dispersed on the surfaces of both domains and across a linker structure. Trypsin digestion and 15N relaxation experiments indicate that the tumbling of the N-terminal and C-terminal domains is effectively independent. These results suggest that ARMET may hold a negatively charged molecule using the two positively charged domains.Solution structure and dynamics of mouse ARMET - Uncorrected ProofJun Hoseki, Hiroaki Sasakawa, Yoshiki Yamaguchi, Momoe Maeda, Hiroshi Kubota, Koichi Kato, Kazuhiro Nagata10.1016/j.febslet.2010.03.008FEBS Letters (2010)2010-03-08FEBS Letters2010-03-08http://www.febsletters.org/article/PIIS0014579310002036/abstract?rss=yesAbstract: 8-oxo-7,8-dihydroadenine (8-oxoAde) is a major product of adenine modification by reactive oxygen species. So far, only one mammalian DNA glycosylase, 8-oxoguanine-DNA-glycosylase 1 (OGG1), has been shown to excise 8-oxoAde, exclusively from pairs with Cyt. We have found that endonuclease VIII-like protein 1 (NEIL1), a mammalian homolog of bacterial endonuclease VIII, can efficiently remove 8-oxoAde from 8-oxoAde:Cyt pairs but not from other contexts. In an in vitro reconstituted system, reactions containing OGG1 produced a fully repaired product, whereas NEIL1 caused an abortive initiation of repair, stopping after 8-oxoAde removal and DNA strand cleavage. This block was partially relieved by polynucleotide kinase/3′-phosphatase. Thus, two alternative routes of 8-oxoAde repair may exist in mammals.The role of mammalian NEIL1 protein in the repair of 8-oxo-7,8-dihydroadenine in DNA - Uncorrected ProofInga R. Grin, Grigory L. Dianov, Dmitry O. Zharkov10.1016/j.febslet.2010.03.009FEBS Letters (2010)2010-03-08FEBS Letters2010-03-08http://www.febsletters.org/article/PIIS0014579310001729/abstract?rss=yesAbstract: Mitochondrial uncoupling proteins (UCPs) are pure anion uniporters, which mediate fatty acid (FA) uniport leading to FA cycling. Protonated FAs then flip-flop back across the lipid bilayer. An existence of pure proton channel in UCPs is excluded by the equivalent flux-voltage dependencies for uniport of FAs and halide anions, which are best described by the Eyring barrier variant with a single energy well in the middle of two peaks. Experiments with FAs unable to flip and alkylsulfonates also support this view. Phylogenetically, UCPs took advantage of the common FA-uncoupling function of SLC25 family carriers and dropped their solute transport function.Channel character of uncoupling protein-mediated transport - Corrected ProofPetr Ježek, Martin Jabůrek, Keith D. Garlid10.1016/j.febslet.2010.02.068FEBS Letters (2010)2010-03-04FEBS Letters2010-03-04REVIEWhttp://www.febsletters.org/article/PIIS0014579310001742/abstract?rss=yesAbstract: Tail-anchored proteins play important roles in protein translocation, membrane fusion and apoptosis. They are targeted to the endoplasmic reticulum membrane via the guided-entry of tail-anchored proteins (Get) pathway. We present the 2Å crystal structure of Get4 which participates in early steps of the Get pathway. The structure shows an α-solenoid fold with particular deviations from the regular pairwise arrangement of α-helices. A conserved hydrophobic groove accommodates the flexible C-terminal region in trans. The structural organization of the Get4 helical hairpin motifs provides a scaffold for protein–protein interactions in the Get pathway.The structure of Get4 reveals an α-solenoid fold adapted for multiple interactions in tail-anchored protein biogenesis - Corrected ProofGunes Bozkurt, Klemens Wild, Stefan Amlacher, Ed Hurt, Bernhard Dobberstein, Irmgard Sinning10.1016/j.febslet.2010.02.070FEBS Letters (2010)2010-03-04FEBS Letters2010-03-04http://www.febsletters.org/article/PIIS0014579310001699/abstract?rss=yesAbstract: The adaptor protein 14-3-3 binds to and stabilizes the tumor suppressor p53 and enhances its anti-tumour activity. In the regulatory C-terminal domain of p53 several 14-3-3 binding motifs have been identified. Here, we report the crystal structure of the extreme C-terminus (residues 385–393, p53pT387) of p53 in complex with 14-3-3σ at a resolution of 1.28Å. p53pT387 is accommodated by 14-3-3 in a yet unrecognized fashion implying a rationale for 14-3-3 binding to the active p53 tetramer. The structure exhibits a potential binding site for small molecules that could stabilize the p53/14-3-3 protein complex suggesting the possibility for therapeutic intervention.Structured summary: MINT-7711943: 14-3-3 sigma (uniprotkb:P31947) and p53 (uniprotkb:P04637) bind (MI:0407) by X-ray crystallography (MI:0114)MINT-7711931: 14-3-3 sigma (uniprotkb:P31947) and p53 (uniprotkb:P04637) bind (MI:0407) by isothermal titration calorimetry (MI:0065)Structure of the p53 C-terminus bound to 14-3-3: Implications for stabilization of the p53 tetramer - Corrected ProofBenjamin Schumacher, Justine Mondry, Philipp Thiel, Michael Weyand, Christian Ottmann10.1016/j.febslet.2010.02.065FEBS Letters (2010)2010-03-03FEBS Letters2010-03-03http://www.febsletters.org/article/PIIS0014579310001705/abstract?rss=yesAbstract: Although the architecture of tripartite multiple drug resistance (MDR) efflux pumps of Gram-negative bacteria has been well characterized, the means by which the components recognize each other and assemble into a functional pump remains obscure. In this study we present evidence that the C-terminal domain of the Pseudomonas aeruginosa OprM and the α-helical hairpin domain of Vibrio cholerae VceA play an important role in the recognition/specificity/recruitment step in the assembly of a functional, VceAB-OprM chimeric efflux pump. To our knowledge, this is the first evidence directly linking the C-terminal domain of an outer membrane efflux protein to its recruitment during the assembly of a tripartite efflux pump.Evidence that the C-terminus of OprM is involved in the assembly of the VceAB-OprM efflux pump - Corrected ProofJiangping Bai, Lakysha Mosley, Joe A. Fralick10.1016/j.febslet.2010.02.066FEBS Letters (2010)2010-03-03FEBS Letters2010-03-03http://www.febsletters.org/article/PIIS0014579310001717/abstract?rss=yesAbstract: We developed an accurate method to predict nucleosome positioning from genome sequences by refining the previously developed method of Peckham et al. (2007) . Here, we used the relative fragment frequency index we developed and a support vector machine to screen for nucleosomal and linker DNA sequences. Our twofold cross-validation revealed that the accuracy of our method based on the area under the receiver operating characteristic curve was 81%, whereas that of Peckham’s method was 75% when both of two nucleosomal sequence data obtained from independent experiments were used for validation. We suggest that our method is more effective in predicting nucleosome positioning.Computational prediction of nucleosome positioning by calculating the relative fragment frequency index of nucleosomal sequences - Corrected ProofRyu Ogawa, Noriyuki Kitagawa, Hiroki Ashida, Rintaro Saito, Masaru Tomita10.1016/j.febslet.2010.02.067FEBS Letters (2010)2010-03-03FEBS Letters2010-03-03http://www.febsletters.org/article/PIIS0014579310001730/abstract?rss=yesAbstract: Ghrelin inhibits insulin secretion partly via induction of IA-2β. However, the orexigenic effect of ghrelin is mediated by the AMP-activated protein kinase (AMPK)–uncoupling protein 2 (UCP2) pathway. Here, we demonstrate that ghrelin’s inhibitory effect on insulin secretion also occurs through the AMPK-UCP2 pathway. Ghrelin increased AMPK phosphorylation and UCP2 mRNA expression in MIN6 insulinoma cells. Overexpression or downregulation of UCP2 attenuated or enhanced insulin secretion, respectively. Furthermore, AMPK activator had a similar effect to ghrelin on UCP2 and insulin secretion in MIN6 cells. In conclusion, ghrelin’s inhibitory effect on insulin secretion is partly mediated by the AMPK-UCP2 pathway, which is independent of the IA-2β pathway.Ghrelin inhibits insulin secretion through the AMPK–UCP2 pathway in β cells - Corrected ProofYing Wang, Masahiro Nishi, Asako Doi, Takeshi Shono, Yasushi Furukawa, Takeshi Shimada, Hiroto Furuta, Hideyuki Sasaki, Kishio Nanjo10.1016/j.febslet.2010.02.069FEBS Letters (2010)2010-03-03FEBS Letters2010-03-03http://www.febsletters.org/article/PIIS0014579310001663/abstract?rss=yesAbstract: Previously, we identified a human ST3Gal-V mRNA variant peculiarly characterized by the presence of a translational start codon localized up-stream and in-frame with the one that is usually considered as unique translation initiation site in the human gene. In this study we demonstrate, by cDNA transfection experiments, mutational analyses, enzyme activity assays, and endoglycosidase-H treatments, that the in vivo expression of this transcript gives rise to two human ST3Gal-V isoforms with distinct characteristics. Produced by a leaky scanning mechanism, they carry different N-glycan structures and exhibit differences in their GM3 synthase activity that might be relevant for the modulation of GM3 cellular content.Two active and differently N-glycosylated isoforms of human ST3Gal-V are produced from the placental mRNA variant by a leaky scanning mechanism - Corrected ProofStefania Zava, Simona Milani, Elena Sottocornola, Bruno Berra, Irma Colombo10.1016/j.febslet.2010.02.062FEBS Letters (2010)2010-02-26FEBS Letters2010-02-26http://www.febsletters.org/article/PIIS0014579310001675/abstract?rss=yesAbstract: MicroRNA-155 (miR-155) has been implicated as a central regulator of the immune system. We have previously reported that miR-155 negatively regulates Helicobacter pylori (H. pylori)-induced inflammation, but the molecular mechanism of miR-155 regulating the inflammation is not fully clear. Here, we identified myeloid differentiation protein 88 (MyD88) as a target gene of miR-155, and found that miR-155 decreased MyD88 expression at the protein but not the mRNA message level, suggesting that the miR-155-mediated inhibition is a post-transcriptional event. Furthermore, the overexpression of miR-155 led to significantly reduced IL-8 production induced by H. pylori infection. Thus, we have demonstrated that miR-155 can negatively regulate inflammation by targeting a key adaptor molecule MyD88 in inflammatory pathways.Identification of MyD88 as a novel target of miR-155, involved in negative regulation of Helicobacter pylori-induced inflammation - Corrected ProofBin Tang, Bin Xiao, Zhen Liu, Na Li, En-Dong Zhu, Bo-Sheng Li, Qing-Hua Xie, Yuan Zhuang, Quan-Ming Zou, Xu-Hu Mao10.1016/j.febslet.2010.02.063FEBS Letters (2010)2010-02-26FEBS Letters2010-02-26http://www.febsletters.org/article/PIIS0014579310001687/abstract?rss=yesAbstract: The in vitro reconstitution of molybdenum nitrogenase was manipulated to generate a chimeric enzyme in which the active site iron–molybdenum cofactor (FeMo-co) is replaced by NifB-co. The NifDK/NifB-co enzyme was unable to reduce N2 to NH3, while exhibiting residual C2H4 and considerable H2 production activities. Production of H2 by NifDK/NifB-co was stimulated by N2 and was dependent on NifH and ATP hydrolysis. Thus, NifDK/NifB-co is a useful tool to gain insights into the catalytic mechanism of nitrogenase. Furthermore, phylogenetic analysis of D and K homologs indicates that several early emerging lineages, which contain NifB, NifH and NifDK encoding genes but which lack other genes required for processing NifB-co into FeMo-co, might encode an enzyme with similar catalytic properties to NifDK/NifB-co.Substrate specificity and evolutionary implications of a NifDK enzyme carrying NifB-co at its active site - Corrected ProofBasem Soboh, Eric S. Boyd, Dehua Zhao, John W. Peters, Luis M. Rubio10.1016/j.febslet.2010.02.064FEBS Letters (2010)2010-02-26FEBS Letters2010-02-26http://www.febsletters.org/article/PIIS0014579310001547/abstract?rss=yesAbstract: Vacuoles play various roles in many physiologically relevant processes in plants. Some of the more prominent are turgor provision, the storage of minerals and nutrients, and cellular signalling. To fulfil these functions a complement of membrane transporters is present at the tonoplast. Prolific patch clamp studies have shown that amongst these, both selective and non-selective ion channels participate in turgor regulation, nutrient storage and signalling. This article reviews the physiological roles, expression patterns and structure function properties of plant vacuolar anion and cation channels that are gated by voltage and ligands.Vacuolar ion channels: Roles in plant nutrition and signalling - Corrected ProofStanislav Isayenkov, Jean Charles Isner, Frans J.M. Maathuis10.1016/j.febslet.2010.02.050FEBS Letters (2010)2010-02-25FEBS Letters2010-02-25REVIEWhttp://www.febsletters.org/article/PIIS001457931000164X/abstract?rss=yesAbstract: Cellular homeostasis is linked tightly to mitochondrial functions. Some damage to mitochondrial proteins and nucleic acids can lead to the depolarization of the inner mitochondrial membrane, thereby sensitizing impaired mitochondria for selective elimination by autophagy. Mitochondrial dysfunction is one of the key aspects of the pathobiology of neurodegenerative disease. Parkin, an E3 ligase located in the cytosol and originally discovered as mutated in monogenic forms of Parkinson’s disease (PD), was found recently to translocate specifically to uncoupled mitochondria and to induce their autophagy.Parkin-mediated selective mitochondrial autophagy, mitophagy: Parkin purges damaged organelles from the vital mitochondrial network - Corrected ProofAtsushi Tanaka10.1016/j.febslet.2010.02.060FEBS Letters (2010)2010-02-25FEBS Letters2010-02-25REVIEWhttp://www.febsletters.org/article/PIIS0014579310001651/abstract?rss=yesAbstract: Autophagosomes (APs) are unique organelles that enwrap cytoplasmic components when necessary. APs then fuse with lysosomes and enclosed materials are degraded. Although approximately 30 autophagy-related genes (ATG) required for AP formation have been identified, fundamental questions on the membrane source or dynamics during the formation remain unresolved. Here, we present a comprehensive overview of the putative membrane sources identified to date.Where do they come from? Insights into autophagosome formation - Corrected ProofMaho Hamasaki, Tamotsu Yoshimori10.1016/j.febslet.2010.02.061FEBS Letters (2010)2010-02-25FEBS Letters2010-02-25REVIEWhttp://www.febsletters.org/article/PIIS0014579310001584/abstract?rss=yesAbstract: Autophagy initiation is strictly dependent on phosphatidylinositol 3-phosphate (PI3P) synthesis. PI3P production is under tight control of PI3Kinase, hVps34, in complex with Beclin-1. Mammalian cells express several PI3P phosphatases that belong to the myotubularin family. Even though some of them have been linked to serious human diseases, their cellular function is largely unknown. Two recent studies indicate that PI3P metabolism involved in autophagy initiation is further regulated by the PI3P phosphatases Jumpy and MTMR3. Additional pools of PI3P, upstream of mTOR and on the endocytic pathway, may modulate autophagy indirectly, suggesting that other PI3P phosphatases might be involved in this process. This review sums up our knowledge on PI3P phosphatases and discusses the recent progress on their role in autophagy.The role of PI3P phosphatases in the regulation of autophagy - Corrected ProofIsabelle Vergne, Vojo Deretic10.1016/j.febslet.2010.02.054FEBS Letters (2010)2010-02-24FEBS Letters2010-02-24REVIEWhttp://www.febsletters.org/article/PIIS0014579310001596/abstract?rss=yesAbstract: S100 proteins are a subfamily of the EF-hand type calcium sensing proteins, the exact biological functions of which have not been clarified yet. In this work, we have identified Cyclophilin 40 (CyP40) and FKBP52 (called immunophilins) as novel targets of S100 proteins. These immunophilins contain a tetratricopeptide repeat (TPR) domain for Hsp90 binding. Using glutathione-S transferase pull-down assays and immunoprecipitation, we have demonstrated that S100A1 and S100A2 specifically interact with the TPR domains of FKBP52 and CyP40 in a Ca2+-dependent manner, and lead to inhibition of the CyP40–Hsp90 and FKBP52–Hsp90 interactions. These findings have suggested that the Ca2+/S100 proteins are TPR-targeting regulators of the immunophilins–Hsp90 complex formations.Structured summary: MINT-7710442: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0915) with S100A6 (uniprotkb:P06703) by competition binding (MI:0405)MINT-7710192: Cyp40 (uniprotkb:P26882) binds (MI:0407) to S100A1 (uniprotkb:P35467) by pull down (MI:0096)MINT-7710412: Cyp40 (uniprotkb:P26882) physically interacts (MI:0915) with S100A2 (uniprotkb:P29034) by competition binding (MI:0405)MINT-7710374: FKBP52 (uniprotkb:Q02790) binds (MI:0407) to S100A2 (uniprotkb:P29034) by pull down (MI:0096)MINT-7710452: Cyp40 (uniprotkb:P26882) physically interacts (MI:0914) with S100A2 (uniprotkb:P29034) and Hsp90 (uniprotkb:P07900) by anti tag coimmunoprecipitation (MI:0007)MINT-7710387: FKBP52 (uniprotkb:Q02790) binds (MI:0407) to S100A6 (uniprotkb:P06703) by pull down (MI:0096)MINT-7710279: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0915) with S100A1 (uniprotkb:P35467) by competition binding (MI:0405)MINT-7710224: FKBP52 (uniprotkb:Q02790) binds (MI:0407) to Hsp90 (uniprotkb:P07900) by pull down (MI:0096)MINT-7710464: Cyp40 (uniprotkb:P26882) physically interacts (MI:0914) with S100A6 (uniprotkb:P06703) and Hsp90 (uniprotkb:P07900) by anti tag coimmunoprecipitation (MI:0007)MINT-7710249: Cyp40 (uniprotkb:P26882) binds (MI:0407) to Hsp90 (uniprotkb:P07900) by pull down (MI:0096)MINT-7710422: Cyp40 (uniprotkb:P26882) physically interacts (MI:0915) with S100A6 (uniprotkb:P06703) by competition binding (MI:0405)MINT-7710348: Cyp40 (uniprotkb:P26882) binds (MI:0407) to S100A2 (uniprotkb:P29034) by pull down (MI:0096)MINT-7710208: FKBP52 (uniprotkb:Q02790) binds (MI:0407) to S100A1 (uniprotkb:P35467) by pull down (MI:0096)MINT-7710265: Cyp40 (uniprotkb:P26882) physically interacts (MI:0915) with S100A1 (uniprotkb:P35467) by competition binding (MI:0405)MINT-7710361: Cyp40 (uniprotkb:P26882) binds (MI:0407) to S100A6 (uniprotkb:P06703) by pull down (MI:0096)MINT-7710476: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0914) with S100A2 (uniprotkb:P29034) and Hsp90 (uniprotkb:P07900) by anti tag coimmunoprecipitation (MI:0007)MINT-7710316: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0914) with S100A1 (uniprotkb:P35467) and Hsp90 (uniprotkb:P07900) by anti tag coimmunoprecipitation (MI:0007)MINT-7710432: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0915) with S100A2 (uniprotkb:P29034) by competition binding (MI:0405)MINT-7710488: FKBP52 (uniprotkb:Q02790) physically interacts (MI:0914) with S100A6 (uniprotkb:P06703) and Hsp90 (uniprotkb:P07900) by anti tag coimmunoprecipitation (MI:0007)MINT-7710329: S100A6 (uniprotkb:P14069) physically interacts (MI:0914) with FKBP52 (uniprotkb:P30416) and Cyp40 (uniprotkb:Q08752) by anti bait coimmunoprecipitation (MI:0006)MINT-7710295: Cyp40 (uniprotkb:P26882) physically interacts (MI:0914) with Hsp90 (uniprotkb:P07900) and S100A1 (uniprotkb:P35467) by anti tag coimmunoprecipitation (MI:0007)S100 proteins regulate the interaction of Hsp90 with Cyclophilin 40 and FKBP52 through their tetratricopeptide repeats - Corrected ProofSeiko Shimamoto, Yasuo Kubota, Hiroshi Tokumitsu, Ryoji Kobayashi10.1016/j.febslet.2010.02.055FEBS Letters (2010)2010-02-24FEBS Letters2010-02-24http://www.febsletters.org/article/PIIS0014579310001602/abstract?rss=yesAbstract: Vitellogenins and other large lipid transfer proteins (LLTP) are well known to play significant roles in the development, metabolism and reproduction of animals. Comparative genomics and phylogenetic analyses of LLTPs using the most comprehensive dataset in metazoans to date are carried out. Our analyses demonstrate that LLTP genes arose significantly earlier, and are more widespread than previously proposed – being present in numerous additional bilaterian and non-bilaterian lineages. A hypothesis is advanced that the most ancestral animal LLTP gene is Vtg, while loss of domains occurred at the bilaterians stem giving rise to apolipoprotein and microsomal triglyceride transfer proteins genes.Comparative genomic and phylogenetic analysis of vitellogenin and other large lipid transfer proteins in metazoans - Corrected ProofAlexander Hayward, Tokiharu Takahashi, William G. Bendena, Stephen S. Tobe, Jerome H.L. Hui10.1016/j.febslet.2010.02.056FEBS Letters (2010)2010-02-24FEBS Letters2010-02-24http://www.febsletters.org/article/PIIS0014579310001614/abstract?rss=yesAbstract: Class IIa histone deacetylases (HDACs) -4, -5, -7 and -9 undergo signal-dependent nuclear export upon phosphorylation of conserved serine residues that are targets for 14-3-3 binding. Little is known of other mechanisms for regulating the subcellular distribution of class IIa HDACs. Using a biochemical purification strategy, we identified protein kinase C-related kinase-2 (PRK2) as an HDAC5-interacting protein. PRK2 and the related kinase, PRK1, phosphorylate HDAC5 at a threonine residue (Thr-292) positioned within the nuclear localization signal (NLS) of the protein. HDAC7 and HDAC9 contain analogous sites that are phosphorylated by PRK, while HDAC4 harbors a non-phosphorylatable alanine residue at this position. We provide evidence to suggest that the unique phospho-acceptor cooperates with the 14-3-3 target sites to impair HDAC nuclear import.Structured summary: MINT-7710106:HDAC5 (uniprotkb:Q9UQL6) physically interacts (MI:0915) with PRK2 (uniprotkb:Q16513) by pull down (MI:0096)Protein kinase C-related kinase targets nuclear localization signals in a subset of class IIa histone deacetylases - Corrected ProofBrooke C. Harrison, Khai Huynh, Greta L. Lundgaard, Steven M. Helmke, M. Benjamin Perryman, Timothy A. McKinsey10.1016/j.febslet.2010.02.057FEBS Letters (2010)2010-02-24FEBS Letters2010-02-24http://www.febsletters.org/article/PIIS0014579310001626/abstract?rss=yesAbstract: The extended Fes-CIP4 homology (EFC)/FCH-BAR (F-BAR) domain tubulates membranes. Overexpression of the pacsin2 EFC/F-BAR domain resulted in tubular localization inside cells and deformed liposomes into tubules in vitro. We found that overexpression of the pacsin2 EFC/F-BAR domain induced cellular microspikes, with the pacsin2 EFC/F-BAR domain concentrated at the neck. The hydrophobic loops and the basic amino-acid residues on the concave surface of the pacsin2 EFC/F-BAR domain are essential for both the microspike formation and tubulation. Since the curvature of the neck of the microspike and that of the tubulation share similar geometry, the pacsin2 EFC/F-BAR domain is considered to facilitate both microspike formation and tubulation.Structured summary: MINT-7710892: EFCS pacsin2 (uniprotkb:Q9UNF0) and EFCS pacsin2 (uniprotkb:Q9UNF0) bind (MI:0407) by X-ray crystallography (MI:0114)Mapping of the basic amino-acid residues responsible for tubulation and cellular protrusion by the EFC/F-BAR domain of pacsin2/Syndapin II - Corrected ProofAtsushi Shimada, Kazunori Takano, Mikako Shirouzu, Kyoko Hanawa-Suetsugu, Takaho Terada, Kiminori Toyooka, Takashi Umehara, Masaki Yamamoto, Shigeyuki Yokoyama, Shiro Suetsugu10.1016/j.febslet.2010.02.058FEBS Letters (2010)2010-02-24FEBS Letters2010-02-24http://www.febsletters.org/article/PIIS0014579310001638/abstract?rss=yesThe aim of this issue entitled “Frontiers in Membrane Biochemistry” is to present the different aspects in this research field dealing with both the role of individual membrane components and basic physical, biochemical and cell biological principles inherent to cellular membrane functioning.Frontiers in membrane biochemistry - Uncorrected ProofSandro Sonnino, Wilhelm Just10.1016/j.febslet.2010.02.059FEBS Letters (2010)2010-02-24FEBS Letters2010-02-24PREFACEhttp://www.febsletters.org/article/PIIS0014579310001535/abstract?rss=yesAbstract: Voltage dependent anion channels (VDACs) have originally been characterised as mitochondrial porins. Starting in the late 1980s, however, evidence began to accumulate that VDACs can also be expressed in plasma membranes. In this review, we briefly revisit the historical milestones in the discovery of plasma membrane-bound VDAC, and we critically analyse the evidence for VDAC plasma membrane localization obtained from various purification strategies and recently from plasma membrane proteomics studies. We discuss the possible biological function and relevance of VDAC in the plasma membrane and finally discuss a hypothetical model of how VDAC may be targeted to the plasma membrane.Voltage dependent anion-selective channel (VDAC) in the plasma membrane - Corrected ProofVito De Pinto, Angela Messina, Darius J.R. Lane, Alfons Lawen10.1016/j.febslet.2010.02.049FEBS Letters (2010)2010-02-23FEBS Letters2010-02-23REVIEWhttp://www.febsletters.org/article/PIIS0014579310001572/abstract?rss=yesSince the discovery of yeast autophagy-related genes (current ATG genes) in the early 1990s, the autophagy research field has grown exponentially. The number of published papers related to autophagy was less than 100 per year before 2000; however, in 2009, it exceeded 1600. Moreover, autophagy has also been discussed not only in scientific journals. There is a very popular Japanese comic (manga) magazine, “Weekly Shonen (means boys) Jump”, with a weekly a circulation of more than 2 million. In two issues in 2009, autophagy appeared in a story in which a hero fought against an enemy. The hero was starved, but was activated by inducing autophagy (unfortunately, the effect did not last long). This magazine told more than 2 million children (and some adults) that we have a unique strategy, autophagy, to survive starvation. This shows how times have changed; just 10years ago, autophagy was of very minor importance even within the scientific community.Autophagy - Corrected ProofNoboru Mizushima10.1016/j.febslet.2010.02.053FEBS Letters (2010)2010-02-23FEBS Letters2010-02-23PREFACEhttp://www.febsletters.org/article/PIIS0014579310001201/abstract?rss=yesAbstract: Recent evidence suggests that ceramide regulates stress signaling via reorganization of the plasma membrane. The focus of this review will be to discuss the mechanism by which acid sphingomyelinase (ASMase)-generated ceramide initiates transmembrane signaling in the plasma membrane exoplasmic leaflet. In particular, we review the unique biophysical properties of ceramide that render it proficient in formation of signaling domains termed ceramide-rich platforms (CRPs), and the role of CRPs in the pathophysiology of various diseases. The biomedical significance of CRPs makes these structures an attractive therapeutic target.Ceramide-rich platforms in transmembrane signaling - Corrected ProofBranka Stancevic, Richard Kolesnick10.1016/j.febslet.2010.02.026FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22REVIEWhttp://www.febsletters.org/article/PIIS0014579310001420/abstract?rss=yesAbstract: Malonyl-CoA-acyl carrier protein transacylase (MCAT) transfers the malonyl group from malonyl-CoA to holo-acyl carrier protein (ACP), and since malonyl-ACP is a key building block for fatty-acid biosynthesis it is considered as a promising antibacterial target. The crystal structures of MCAT from Staphylococcus aureus and Streptococcus pneumoniae have been determined at 1.46 and 2.1Å resolution, respectively. In the SaMCAT structure, the N-terminal expression peptide of a neighboring molecule running in the opposite direction of malonyl-CoA makes extensive interactions with the highly conserved “Gly-Gln-Gly-Ser-Gln” stretch, suggesting a new design platform. Mutagenesis results suggest that Ser91 and His199 are the catalytic dyad.New design platform for malonyl-CoA-acyl carrier protein transacylase - Corrected ProofSeung Kon Hong, Kook Han Kim, Joon Kyu Park, Ki-Woong Jeong, Yangmee Kim, Eunice EunKyeong Kim10.1016/j.febslet.2010.02.038FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22http://www.febsletters.org/article/PIIS0014579310001432/abstract?rss=yesAbstract: Here we report that deletion of SOD1, the Cu,Zn-superoxide dismutase in Saccharomyces cerevisiae is sensitive to cell wall-perturbing agents, such as Calcofluor white and Congo red. The sensitivity was restored by retransformation with wild type SOD1 or the addition of N-acetylcysteine or reduced glutathione to the medium. Additionally, the accumulation of reactive oxygen species was observed in sod1Δ mutant in the presence of Calcofluor white or Congo red. Cell wall analysis indicated an increase of cell wall chitin and cell wall thickness in sod1Δ mutant compared to wild type. These results indicate a novel direct connection between antioxidative functions and cell wall homeostasis.Cu,Zn-superoxide dismutase is required for cell wall structure and for tolerance to cell wall-perturbing agents in Saccharomyces cerevisiae - Corrected ProofXiangyong Liu, Xiaohua Zhang, Zhaojie Zhang10.1016/j.febslet.2010.02.039FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22http://www.febsletters.org/article/PIIS0014579310001444/abstract?rss=yesAbstract: Initial characterizations of live-Salmonella-containing early (LSEP) and late phagosomes (LSLP) in macrophages show that both phagosomes retain Rab5 and EEA1. In addition, LSEP specifically contain transferrin receptor whereas LSLP possess relatively more rabaptin-5. In contrast to LSLP, late-Salmonella-containing vacuoles in epithelial cells show significantly reduced levels of Rab5 and EEA1. Subsequent results demonstrate that both phagosomes efficiently fuse with early endosomes (EE). In contrast to LSEP, fusion between LSLP and EE is insensitive to ATPγS treatment. Furthermore, LSLP fuses with EE in absence of NEM-sensitive fusion factor (NSF) as well as in the presence of NSF:D1EQ mutant demonstrating that LSLP fusion with EE is NSF independent.NSF independent fusion of Salmonella-containing late phagosomes with early endosomes - Corrected ProofSeetharaman Parashuraman, Richa Madan, Amitabha Mukhopadhyay10.1016/j.febslet.2010.02.040FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22http://www.febsletters.org/article/PIIS0014579310001456/abstract?rss=yesAbstract: Viperin, an interferon-inducible antiviral protein, is shown to bind an iron-sulfur cluster, based on iron analysis as well as UV–Vis and electron paramagnetic resonance spectroscopic data. The reduced protein contains a [4Fe-4S]1+ cluster whose g-values are altered upon addition of S-adenosylmethionine (SAM), consistent with SAM coordination to the cluster. Incubation of reduced viperin with SAM results in reductive cleavage of SAM to produce 5′-deoxyadenosine (5′-dAdo), a reaction characteristic of the radical SAM superfamily. The 5′-dAdo cleavage product was identified by a combination of HPLC and mass spectrometry analysis.The antiviral protein viperin is a radical SAM enzyme - Corrected ProofKaitlin S. Duschene, Joan B. Broderick10.1016/j.febslet.2010.02.041FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22http://www.febsletters.org/article/PIIS0014579310001468/abstract?rss=yesAbstract: Mitochondrial peroxiredoxin 3 (Prx 3) is rapidly oxidized in cells exposed to phenethyl isothiocyanate (PEITC) and auranofin (AFN), but the mechanism of oxidation is unclear. Using HL-60 cells deplete of mitochondrial DNA we show that peroxiredoxin 3 oxidation and cytotoxicity requires a functional respiratory chain. Thioredoxin reductase (TrxR) could be inhibited by up to 90% by auranofin without direct oxidation of peroxiredoxin 3. However, inhibition of thioredoxin reductase promoted peroxiredoxin 3 oxidation and cytotoxicity in combination with phenethyl isothiocyanate or antimycin A. We conclude that rapid peroxiredoxin 3 oxidation occurs as a consequence of increased oxidant production from the mitochondrial respiratory chain.Mitochondrial respiratory chain involvement in peroxiredoxin 3 oxidation by phenethyl isothiocyanate and auranofin - Corrected ProofKristin K. Brown, Andrew G. Cox, Mark B. Hampton10.1016/j.febslet.2010.02.042FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22http://www.febsletters.org/article/PIIS001457931000147X/abstract?rss=yesAbstract: The CDC25B phosphatase regulates the activation of CDK1–Cyclin B at the onset of mitosis, being a key target of the checkpoint pathways activated by cellular stress and DNA damage. Previous work has reported that checkpoint activation induces the sequestration of CDC25B in the cytoplasm. Here we show that in response to UV irradiation, the levels of CDC25B protein can be downregulated independently of classical checkpoints pathways such as p53, ATM/ATR and p38 MAPK. We also show that translational repression mediated by eIF2α phosphorylation regulates CDC25B expression levels. Taken together, our results illustrate a new mechanism of CDC25B regulation in response to stress.UV-induced downregulation of the CDC25B protein in human cells - Corrected ProofMatthieu Lemaire, Bernard Ducommun, Angel R. Nebreda10.1016/j.febslet.2010.02.043FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22http://www.febsletters.org/article/PIIS0014579310001481/abstract?rss=yesAbstract: Heparin Binding Hemagglutinin A (HBHA) is hitherto the sole virulence factor associated with tuberculosis dissemination from the lungs, the site of primary infection, to epithelial cells. We have previously reported the solution structure of HBHA, a dimeric and elongated molecule. Since oligomerisation of HBHA is associated with its ability to induce bacterial agglutination, we investigated this process using experimental and modelling techniques. We here identified a short segment of HBHA whose presence is mandatory for the stability of folded conformation, whose denaturation is a reversible two-state process. Our data suggest that agglutination-driven cell–cell interactions do not occur via association of HBHA monomers, nor via association of HBHA dimers and open the scenario to a possible trans-dimerisation process.Structured summary: MINT-7709940, MINT-7709948: HBHA (uniprotkb:A5TZK3) and HBHA (uniprotkb:A5TZK3) bind (MI:0407) by circular dichroism (MI:0016)MINT-7709966: HBHA (uniprotkb:A5TZK3) and HBHA (uniprotkb:A5TZK3) bind (MI:0407) by biophysical (MI:0013)MINT-7709955: HBHA (uniprotkb:A5TZK3) and HBHA (uniprotkb:A5TZK3) bind (MI:0407) by dynamic light scattering (MI:0038)Dimerisation and structural integrity of Heparin Binding Hemagglutinin A from Mycobacterium tuberculosis: Implications for bacterial agglutination - Corrected ProofCarla Esposito, Paola Carullo, Emilia Pedone, Giuseppe Graziano, Pompea Del Vecchio, Rita Berisio10.1016/j.febslet.2010.02.044FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22http://www.febsletters.org/article/PIIS0014579310001493/abstract?rss=yesAbstract: Myogenic, or pressure-induced, vasoconstriction is critical for local blood flow autoregulation. Underlying this vascular smooth muscle (VSM) response are events including membrane depolarization, Ca2+ entry and mobilization, and activation of contractile proteins. Large conductance, Ca2+-activated K+ channel (BKCa) has been implicated in several of these steps including, (1) channel closure causing membrane depolarization, and (2) channel opening causing hyperpolarization to oppose excessive pressure-induced vasoconstriction. As multiple mechanisms regulate BKCa activity (subunit composition, membrane potential (Em) and Ca2+ levels, post-translational modification) tissue level diversity is predicted. Importantly, heterogeneity in BKCa channel activity may contribute to tissue-specific differences in regulation of myogenic vasoconstriction, allowing local hemodynamics to be matched to metabolic requirements. Knowledge of such variability will be important to exploiting the BKCa channel as a therapeutic target and understanding systemic effects of its pharmacological manipulation.Large conductance, Ca2+-activated K+ channels (BKCa) and arteriolar myogenic signaling - Corrected ProofMichael A. Hill, Yan Yang, Srikanth R. Ella, Michael J. Davis, Andrew P. Braun10.1016/j.febslet.2010.02.045FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22REVIEWhttp://www.febsletters.org/article/PIIS001457931000150X/abstract?rss=yesAbstract: The study of mitochondrial ion channels changed our perception of these double-wrapped organelles from being just the power house of a cell to the guardian of a cell’s fate. Mitochondria communicate with the cell through these special channels. Most of the time, the message is encoded by ion flow across the mitochondrial outer and inner membranes. Potassium, sodium, calcium, protons, nucleotides, and proteins traverse the mitochondrial membranes in an exquisitely regulated manner to control a myriad of processes, from respiration and mitochondrial morphology to cell proliferation and cell death. This review is an update on both well established and putative mitochondrial channels regarding their composition, function, regulation, and therapeutic potential.Mitochondrial ion channels as therapeutic targets - Corrected ProofPablo M. Peixoto, Shin-Young Ryu, Kathleen W. Kinnally10.1016/j.febslet.2010.02.046FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22REVIEWhttp://www.febsletters.org/article/PIIS0014579310001511/abstract?rss=yesAbstract: Single-molecule tracking and fluorescence correlation spectroscopy (FCS) applied to the plasma membrane in living cells have allowed a number of unprecedented observations, thus fostering a new basic understanding of molecular diffusion, interaction, and signal transduction in the plasma membrane. It is becoming clear that the plasma membrane is a heterogeneous entity, containing diverse structures on nano-meso-scales (2–200nm) with a variety of lifetimes, where certain membrane molecules stay together for limited durations. Molecular interactions occur in the time-dependent inhomogeneous two-dimensional liquid of the plasma membrane, which might be a key for plasma membrane functions.Hierarchical organization of the plasma membrane: Investigations by single-molecule tracking vs. fluorescence correlation spectroscopy - Corrected ProofAkihiro Kusumi, Yuki M. Shirai, Ikuko Koyama-Honda, Kenichi G.N. Suzuki, Takahiro K. Fujiwara10.1016/j.febslet.2010.02.047FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22REVIEWhttp://www.febsletters.org/article/PIIS0014579310001523/abstract?rss=yesAbstract: Mitochondrial potassium channels play an important role in cytoprotection. Potassium channels in the inner mitochondrial membrane are modulated by inhibitors and activators (potassium channel openers) previously described for plasma membrane potassium channels. The majority of mitochondrial potassium channel modulators exhibit a broad spectrum of off-target effects. These include uncoupling properties, inhibition of the respiratory chain and effects on cellular calcium homeostasis. Therefore, the rational application of channel inhibitors or activators is crucial to understanding the cellular consequences of mitochondrial channel inhibition or activation. Moreover, understanding their side-effects should facilitate the design of a specific mitochondrial channel opener with cytoprotective properties. In this review, we discuss the complex interactions of potassium channel inhibitors and activators with cellular structures.Pharmacology of mitochondrial potassium channels: dark side of the field - Corrected ProofAdam Szewczyk, Anna Kajma, Dominika Malinska, Antoni Wrzosek, Piotr Bednarczyk, Barbara Zabłocka, Krzysztof Dołowy10.1016/j.febslet.2010.02.048FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22REVIEWhttp://www.febsletters.org/article/PIIS0014579310001559/abstract?rss=yesAbstract: MotA and MotB form the proton-channel complex of the proton-driven bacterial flagellar motor. A plug segment of Escherichia coli MotB suppresses proton leakage through the MotA/B complex when it is not assembled into the motor. Using a ratiometric pH indicator protein, pHluorin, we show that the proton-conductivity of a Salmonella MotA/B complex not incorporated into the motor is two orders of magnitude lower than that of a complex that is incorporated and activated. This leakage is, however, significant enough to change the cytoplasmic pH to a level at which the chemotaxis signal transduction system responds.Proton-conductivity assay of plugged and unplugged MotA/B proton channel by cytoplasmic pHluorin expressed in Salmonella - Corrected ProofYusuke V. Morimoto, Yong-Suk Che, Tohru Minamino, Keiichi Namba10.1016/j.febslet.2010.02.051FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22http://www.febsletters.org/article/PIIS0014579310001560/abstract?rss=yesAbstract: HlyU is a transcription factor of the ArsR/SmtB family and activates the expression of the pathogenic Vibrio vulnificus RTX toxin. In contrast to the other metal-responding ArsR/SmtB proteins, HlyU does not sense metal ions. To provide its structural information, we elucidated the crystal structure of HlyU from V. vulnificus CMCP6 (HlyU_Vv). The monomeric HlyU_Vv architecture of five α-helices and two β-strands, some of which constitute a typical DNA-binding winged helix-turn-helix (wHTH) motif, is very similar to that of other transcription regulators. Nonetheless, the homo-dimeric HlyU_Vv structure shows several different, three-dimensional features in the spatial position and the detailed dimeric interaction, which were not observed in the modeling study based on the same protein family and sequence similarity.Structured summary: MINT-7710072, MINT-7710086: HlyU_Vv (uniprotkb:Q8DES3) and HlyU_Vv (uniprotkb:Q8DES3) bind (MI:0407) by X-ray crystallography (MI:0114)Crystal structure of the transcriptional activator HlyU from Vibrio vulnificus CMCP6 - Corrected ProofKosuke Nishi, Hyun-Ju Lee, Suk-Youl Park, Soo Jang Bae, Shee Eun Lee, Paul D. Adams, Joon Haeng Rhee, Jeong-Sun Kim10.1016/j.febslet.2010.02.052FEBS Letters (2010)2010-02-22FEBS Letters2010-02-22http://www.febsletters.org/article/PIIS0014579310001389/abstract?rss=yesAbstract: A link between cellular uptake of high density lipoprotein (HDL) and regulation of sterol regulatory element-binding protein-1 (SREBP-1) was investigated in vitro. HDL decreased nuclear SREBP-1 levels as well as SREBP-1 target gene expression in HepG2 and HEK293 cells. However, HDL did not repress an exogenously expressed, constitutively active form of SREBP-1. HDL increased cellular cholesterol levels, and cellular cholesterol depletion by methyl-β-cyclodextrin abolished the effects of HDL. These results suggest that HDL inhibits the activation of SREBP-1 through a cholesterol-dependent mechanism, which may play an important role in regulating lipid synthetic pathways mediated by SREBP-1.High density lipoprotein inhibits the activation of sterol regulatory element-binding protein-1 in cultured cells - Corrected ProofMasaki Yoshida, Nagakatsu Harada, Keiko Yoshida, Tadahiko Nakagawa, Takaaki Shimohata, Kazuaki Mawatari, Akira Takahashi, Hiroshi Sakaue, Yutaka Nakaya10.1016/j.febslet.2010.02.034FEBS Letters (2010)2010-02-18FEBS Letters2010-02-18