FEBS Letters RSS feed: Current Issue. 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/?rss=yesElsevier Inc.en © 2012 Federation of European Biochemical Societies. Published by Elsevier Inc. All rights reserved. FEBS Letters0014-57935861021 May 2012 © 2012 Federation of European Biochemical Societies. Published by Elsevier Inc. All rights reserved. healthpermissions@elsevier.comhttp://www.febsletters.org/article/PIIS0014579312003420/abstract?rss=yesEditorial Board10.1016/S0014-5793(12)00342-0FEBS Letters 586, 10 (2012)2012-05-21FEBS Letters2012-05-2158610S0014-5793(12)X0010-3iihttp://www.febsletters.org/article/PIIS0014579312002840/abstract?rss=yesThe mini-review series on ubiquitin-related tumor suppressors (TSs) continues the FEBS Letters “FOCUS ON…” serial on TS proteins. Previous issues were covering LKB1/AMPK signaling and metastasis suppressors . In the present issue, the focus lies on proteins implicated in human cancers and tumorigenesis through their ability to either interfere with or be part of the ubiquitin system. In this context, Wang and Jiang refer to Mdm2, a mono-ubiquitin E3 ligase that by interacting with MdmX is converted to a p53 poly-ubiquitin E3 ligase regulating p53 degradation. A group of key factors, such as p53, p73, PolH and c-Myc, involved in DNA damage response, is regulated by Pirh2 (p53-induced RING-H2) protein also known as Rchy1. Jung et al. report on Pirh2, which is found up- or down-regulated in different types of cancer, and hence is implicated in either promoting or suppressing tumor progression . The neurofibromatosis type 2 (NF2) gene encodes merlin, a protein that has been shown to suppress mitogenic signaling both at the plasma membrane and in the nucleus. Zhou and Hahnemann discuss the function of merlin, that while inhibiting signaling by integrins and receptor tyrosine kinases in the nucleus, suppresses the E3 ubiquitin ligase CRL4DCAF1 to inhibit proliferation . Finally, Wang et al. review the F-box and WD repeat domain-containing 7 (FBW7) protein, which has been characterized as an onco-suppressor protein in human cancers. FBW7 recruits the SCF (SKP1-CUL1-F-box protein) complex to form a functional E3 ligase. Both the major substrates and its upstream regulatory factors are discussed, highlighting the essential role of FBW7 in carcinogenesis.FOCUS ON… Ubiquitin-related tumor suppressorsWilhelm W. Just10.1016/j.febslet.2012.04.006FEBS Letters 586, 10 (2012)2012-04-16FEBS Letters2012-04-1658610S0014-5793(12)X0010-3Focus on... Ubiquitin-Related Tumor Suppressors13891389http://www.febsletters.org/article/PIIS0014579312001731/abstract?rss=yesHighlights: ► Mdm2 catalyzes p53 monoubiquitination at multiple sites. ► Mdm2/Mdmx promotes p53 polyubiquitination. ► P53-inducing signals convert MdmX into a preferred Mdm2/MdmX substrate. ► E4 factors promote p53 polyubiquitination in the presence of Mdm2. ► Specific deubiquitinases antagonize ubiquitination p53, Mdmx and/or Mdm2.Abstract: Mdm2 regulates the stability, translation, subcellular localization and transcriptional activity of p53 protein. Mdm2-dependent p53 inhibition is essential in regulating p53 activity during embryonic development and in adult tissues. MdmX, an Mdm2 homolog, is also essential for p53 inhibition in vivo. Recent advances in the field from biochemical and genetic studies have revealed an essential role for the MdmX RING domain in Mdm2-dependent p53 polyubiquitination and degradation. Mdm2 on its own is a monoubiquitin E3 ligase for p53, but is converted to a p53 polyubiquitin E3 ligase by MdmX through their RING–RING domain interactions. MdmX acts as an activator as well as a substrate of Mdm2/MdmX E3 complex. The insufficiency of Mdm2 for p53 polyubiquitination also demands other p53 E3 ligases or E4 factors be incorporated into the p53 degradation arena. Deubiquitinases nullify the effects of E3 actions and reverse the ubiquitination process, which permits a diverse and dynamic pattern of p53 stability control. Unsurprisingly, stress signals target MdmX to disengage the p53/Mdm2 feedback loop for timely and appropriate p53 responses to these stresses.Mdm2 and MdmX partner to regulate p53Xinjiang Wang, Xuejun Jiang10.1016/j.febslet.2012.02.049FEBS Letters 586, 10 (2012)2012-03-09FEBS Letters2012-03-0958610S0014-5793(12)X0010-3Focus on... Ubiquitin-Related Tumor Suppressors13901396http://www.febsletters.org/article/PIIS0014579312002529/abstract?rss=yesAbstract: The ubiquitin-dependent proteasome system plays a critical role in many cellular processes and pathogenesis of various human diseases, including cancer. Although there are a large number of E3 ubiquitin ligases, the majority are RING-finger type E3s. Pirh2, a target of p53 transcription factor, contains a highly conserved C3H2C3 type RING domain. Importantly, Pirh2 was found to regulate a group of key factors dedicated to the DNA damage response, such as p53, p73, PolH, and c-Myc. Interestingly, Pirh2 was upregulated or downregulated in different types of cancers. These suggest that Pirh2 is implicated in either promoting or suppressing tumor progression in a tissue-dependent manner. This review will focus on the major findings in these studies and discuss the potential to explore Pirh2 as a cancer therapeutic target.Pirh2 RING-finger E3 ubiquitin ligase: Its role in tumorigenesis and cancer therapyYong-Sam Jung, Yingjuan Qian, Xinbin Chen10.1016/j.febslet.2012.03.052FEBS Letters 586, 10 (2012)2012-04-04FEBS Letters2012-04-0458610S0014-5793(12)X0010-3Focus on... Ubiquitin-Related Tumor Suppressors13971402http://www.febsletters.org/article/PIIS0014579312002037/abstract?rss=yesAbstract: Recent evidence suggests that the neurofibromatosis type 2 (NF2) gene encoded protein merlin suppresses mitogenic signalling not only at the cell membrane but also in the nucleus. At the membrane, merlin inhibits signalling by integrins and tyrosine receptor kinases (RTKs) and the activation of downstream pathways, including the Ras/Raf/MEK/ERK, FAK/Src, PI3K/AKT, Rac/PAK/JNK, mTORC1, and Wnt/β-catenin pathways. In the nucleus, merlin suppresses the E3 ubiquitin ligase CRL4DCAF1 to inhibit proliferation. Gene expression analysis suggested that CRL4DCAF1 could also regulate the expression of integrins and RTKs. In this review, we explore the links between merlin function at the membrane and in the nucleus, and discuss the potential of targeting the master regulator CRL4 DCAF1 to treat NF2 and other merlin-deficient tumours.Merlin, a multi-suppressor from cell membrane to the nucleusLu Zhou, C. Oliver Hanemann10.1016/j.febslet.2012.03.016FEBS Letters 586, 10 (2012)2012-03-22FEBS Letters2012-03-2258610S0014-5793(12)X0010-3Focus on... Ubiquitin-Related Tumor Suppressors14031408http://www.febsletters.org/article/PIIS0014579312002049/abstract?rss=yesHighlights: ► FBW7 is a F-box protein in SCF E3 ligase complex. ► FBW7 substrates include Cyclin E, c-Myc, c-Jun, Notch, Mcl-1, mTOR, HIF-1α, etc. ► FBW7 functions as a tumor suppressor protein in human malignancies.Abstract: FBW7 (F-box and WD repeat domain-containing 7) has been characterized as an onco-suppressor protein in human cancers. Recent studies have also shown that FBW7 exerts its anti-tumor function primarily by promoting the degradation of various oncoproteins, through which FBW7 regulates cellular proliferation, differentiation and causes genetic instability. In this review, we will discuss the role of FBW7 downstream substrates and how dysregulation of Fbw7-mediated proteolysis of these substrates contributes to tumorigenesis. Additionally, we will also summarize the currently available various Fbw7-knockout mouse models that support Fbw7 as a tumor suppressor gene in the development and progression of human malignancies.Tumor suppressor functions of FBW7 in cancer development and progressionZhiwei Wang, Hiroyuki Inuzuka, Jiateng Zhong, Lixin Wan, Hidefumi Fukushima, Fazlul H. Sarkar, Wenyi Wei10.1016/j.febslet.2012.03.017FEBS Letters 586, 10 (2012)2012-03-22FEBS Letters2012-03-2258610S0014-5793(12)X0010-3Focus on... Ubiquitin-Related Tumor Suppressors14091418http://www.febsletters.org/article/PIIS0014579312002761/abstract?rss=yesHighlights: ► Ser-32 phosphorylation reciprocally modulates the activities of liver PFK-2/FBPase-2. ► Dimerization of PFK-2/FBPase-2 was analyzed by fluorescence-based assays. ► Preferentially two Ser-32 phosphorylated PFK-2/FBPase-2 proteins interact. ► Conformational changes of PFK-2/FBPase-2 are crucial for the metabolic response in liver.Abstract: The bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFK-2/FBPase-2) is a key regulator of carbohydrate metabolism in liver. The goal of this study was to elucidate the regulatory role of Ser-32 phosphorylation on the kinase domain mediated dimerization of PFK-2/FBPase-2. Fluorescence-based mammalian two-hybrid and sensitized emission fluorescence resonance energy transfer analyses in cells revealed preferential binding within homodimers in contrast to heterodimers. Using isolated proteins a close proximity of two PFK-2/FBPase-2 monomers was only detectable in the phosphorylated enzyme dimer. Thus, a flexible kinase interaction mode exists, suggesting dimer conformation mediated coupling of hormonal and posttranslational enzyme regulation to the metabolic response in liver.Structured summary of protein interactions: PFK-2/FBPase-2 physically interacts with PFK-2/FBPase-2 by fluorescent resonance energy transfer (View Interaction: 1, 2)PFK-2/FBPase-2 physically interacts with PFK-2/FBPase-2 by two hybrid (View interaction)Dimer interface rearrangement of the 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase rat liver isoenzyme by cAMP-dependent Ser-32 phosphorylationSara Langer, David A. Okar, Julia Schultz, Sigurd Lenzen, Simone Baltrusch10.1016/j.febslet.2012.03.066FEBS Letters 586, 10 (2012)2012-04-20FEBS Letters2012-04-2058610S0014-5793(12)X0010-3Research Letters with SDA14191425http://www.febsletters.org/article/PIIS0014579312002864/abstract?rss=yesHighlights: ► Gcap14 is a newly found microtubule-associated protein in mammals. ► Gcap14 is shown to bind to microtubules directly. ► Gcap14 induces bundling of microtubules in vitro.Abstract: Microtubules form flexible fibers, which are utilized in cell proliferation and differentiation. Although the flexibility of microtubules was shown to be regulated by various microtubule-associated proteins, this regulation is still far from complete understanding. Here, we report a new potential regulator of microtubules in mammals. Gcap14 colocalizes with microtubules in mammalian cells transfected with Gcap14 expression vector. Association of Gcap14 with microtubules was confirmed by biochemical subcellular fractionation. Recombinant Gcap14 protein cosedimented with pure microtubules, indicating a direct binding between the two. Furthermore, recombinant Gcap14 was shown to have the ability of inducing microtubule bundling in vitro.Structured summary of protein interactions: Gcap14 physically interacts with Gcap14 by anti tag coimmunoprecipitation (View Interaction: 1, 2)The murine Gcap14 gene encodes a novel microtubule binding and bundling proteinHitomi Hosono, Nao Yamaguchi, Kenzi Oshima, Tsukasa Matsuda, Daita Nadano10.1016/j.febslet.2012.04.008FEBS Letters 586, 10 (2012)2012-04-19FEBS Letters2012-04-1958610S0014-5793(12)X0010-3Research Letters with SDA14261430http://www.febsletters.org/article/PIIS0014579312003055/abstract?rss=yesHighlights: ► THAP11 is a physiological binding partner of PCBP1. ► THAP11 negatively regulates CD44 alternative splicing and tumor cell invasion depending on the interaction with PCBP1. ► The expression of THAP11 mRNA is significantly correlated with PCBP1 mRNA in HCC patients.Abstract: THAP11 is an essential factor involved in ES cell pluripotency and cell growth. Here, we identified THAP11 as a novel physiological binding partner of PCBP1. In HepG2 cells, THAP11 overexpression inhibited CD44 v6 expression and cell invasion. However, when deleting the binding domain with PCBP1 or endogenous PCBP1 was knocked down, THAP11 failed to inhibit CD44 v6 expression, indicating that THAP11 regulates CD44 v6 expression through interacting with PCBP1. In HCC patients, the expression of THAP11 mRNA significantly correlated with PCBP1 mRNA expression. Our results suggest a novel role of THAP11 in CD44 alternative splicing and hepatoma invasion.Structured summary of protein interactions:THAP11 physically interacts with PCBP1 by anti bait coimmunoprecipitation (View interaction) THAP11 physically interacts with PCBP1 by anti tag coimmunoprecipitation (View Interaction: 1, 2) THAP11 and PCBP1 colocalize by fluorescence microscopy (View interaction)THAP11, a novel binding protein of PCBP1, negatively regulates CD44 alternative splicing and cell invasion in a human hepatoma cell lineWen-Xi Lian, Rong-Hua Yin, Xiang-Zhen Kong, Tong Zhang, Xian-Hong Huang, Wei-Wei Zheng, Yang Yang, Yi-Qun Zhan, Wang-Xiang Xu, Miao Yu, Chang-Hui Ge, Jun-Tang Guo, Chang-Yan Li, Xiao-Ming Yang10.1016/j.febslet.2012.04.016FEBS Letters 586, 10 (2012)2012-04-23FEBS Letters2012-04-2358610S0014-5793(12)X0010-3Research Letters with SDA14311438http://www.febsletters.org/article/PIIS0014579312003092/abstract?rss=yesHighlights: ► Phosphoryl groups in the biphosphorylated complex exhibit characteristic dynamics. ► The dynamics occurs in a millisecond time scale at the active site of HPr. ► The time scale is comparable to the phosphoryl transfer rate between EIN and HPr. ► The dynamics of HPr may be important to interact with multiple partner proteins.Abstract: The N-terminal domain of Enzyme I (EIN) and phosphocarrier HPr can form a biphosphorylated complex when they are both phosphorylated by excess cellular phosphoenolpyruvate. Here we show that the electrostatic repulsion between the phosphoryl groups in the biphosphorylated complex results in characteristic dynamics at the active site in a millisecond time scale. The dynamics is localized to phospho-His15 and the stabilizing backbone amide groups of HPr, and does not impact on the phospho-His189 of EIN. The dynamics occurs with the kex of ∼500s−1 which compares to the phosphoryl transfer rate of ∼850s−1 between EIN and HPr. The conformational dynamics in HPr may be important for its phosphotransfer reactions with multiple partner proteins.Structured summary of protein interactions: EIN and HPr bind by nuclear magnetic resonance (View Interaction).Active site phosphoryl groups in the biphosphorylated phosphotransferase complex reveal dynamics in a millisecond time scaleTae-Kyung Yu, Young-Joo Yun, Ko On Lee, Kyung Jun Ahn, Jeong-Yong Suh10.1016/j.febslet.2012.04.020FEBS Letters 586, 10 (2012)2012-04-23FEBS Letters2012-04-2358610S0014-5793(12)X0010-3Research Letters with SDA14391444http://www.febsletters.org/article/PIIS0014579312003134/abstract?rss=yesHighlights: ► The subcellular distribution of syntenin-1 is regulated by its N- and C-termini. ► A phosphorylation switch may regulate the N-terminal autoinhibition. ► The PDZ tandem and the C-terminus cooperate in membrane targeting of syntenin-1. ► Electrostatic interactions contribute to syntenin-1 membrane targeting.Abstract: Syntenin-1 is a PDZ protein involved in receptor recycling and clustering. Its two PDZ domains interact with various receptors and phosphoinositides, and are flanked by N- and C-terminal regions. Here, we report the identification of an autoinhibitory peptide stretch in the N-terminus that might be regulated by phosphorylation. We further establish that basic residues in the C-terminal region mediate electrostatic interactions with reconstituted liposomes and contribute to the plasma membrane targeting. Our study adds new components to the multi-dentate membrane targeting mechanism and highlights the role of N- and C-terminal PDZ extensions in the regulation of syntenin-1 plasma membrane localization.Structured summary of protein interactions: PDZ1-PDZ2 and peptide bind by fluorescence technology (View Interaction: 1, 2, 3, 4).Extensions of PSD-95/discs large/ZO-1 (PDZ) domains influence lipid binding and membrane targeting of syntenin-1Anna Maria Wawrzyniak, Elke Vermeiren, Pascale Zimmermann, Ylva Ivarsson10.1016/j.febslet.2012.04.024FEBS Letters 586, 10 (2012)2012-04-23FEBS Letters2012-04-2358610S0014-5793(12)X0010-3Research Letters with SDA14451451http://www.febsletters.org/article/PIIS0014579312002578/abstract?rss=yesHighlights: ► A multi-parameter approach to visualize intracellular signaling events in the live B cell. ► The subcellular translocation of signaling proteins precedes Ca2+ mobilization. ► Various organelles participate in a timely-ordered manner to Ca2+ mobilization.Abstract: Antigen-induced B cell activation requires mobilization of the Ca2+ second messenger. This process is associated with the subcellular relocalization of signal effector proteins of the B cell antigen receptor such as the adaptor protein SLP65. Here we describe a broadly applicable live cell imaging method to simultaneously visualize intracellular Ca2+ flux profiles and the translocation of cytosolic signaling proteins to the plasma membrane in real time. Our approach delineated the kinetic hierarchy of Ca2+ signaling events in B cells and revealed a timely ordered contribution of various organelles to the overall Ca2+ signal. The developed experimental setup provides a useful tool to resolve the spatiotemporal signaling dynamics in various receptor signaling systems.Spatiotemporal resolution of Ca2+ signaling events by real time imaging of single B cellsStephan Junek, Michael Engelke, Detlev Schild, Jürgen Wienands10.1016/j.febslet.2012.03.057FEBS Letters 586, 10 (2012)2012-04-13FEBS Letters2012-04-1358610S0014-5793(12)X0010-3Research Letters14521458http://www.febsletters.org/article/PIIS0014579312002694/abstract?rss=yesHighlights: ► Bacterial adhesion to human cells and its inhibition with new mannosides was shown. ► We conclude that mannan is a fair model for highly mannosylated cell surfaces. ► Cytotoxicity of tested mannosides was determined and the biocompatibility indices determined. ► A novel mannosidic squaric acid derivative was identified as new lead compound. ► The glycobiological potential of specific mannosides for an anti-adhesion approach was shown.Abstract: Bacterial adhesion to glycosylated surfaces is a key issue in human health and disease. Inhibition of bacterial adhesion by suitable carbohydrates could lead to an anti-adhesion therapy as a novel approach against bacterial infections. A selection of five α-mannosides has been evaluated as inhibitors of bacterial adhesion to the polysaccharide mannan, as well as to the surface of live human HT-29 cells. Cell toxicity studies were performed to identify the therapeutic window for a potential in vivo-application of the tested carbohydrates. A previously published mannosidic squaric acid diamide was shown to be exceptionally effective as inhibitor of the bacterial lectin FimH.Inhibition of bacterial adhesion to live human cells: Activity and cytotoxicity of synthetic mannosidesMirja Hartmann, Heike Papavlassopoulos, Vijayanand Chandrasekaran, Carsten Grabosch, Femke Beiroth, Thisbe K. Lindhorst, Claudia Röhl10.1016/j.febslet.2012.03.059FEBS Letters 586, 10 (2012)2012-04-11FEBS Letters2012-04-1158610S0014-5793(12)X0010-3Research Letters14591465http://www.febsletters.org/article/PIIS0014579312002773/abstract?rss=yesHighlights: ► GnRH induces ACTN4 nuclear translocation. ► ACTN4 is involved in the regulation of mFshβ gene transcription. ► C-terminal CaM-like domain of ACTN4 is crucial for the above regulation. ► Both Ca2+ signaling pathway and MAPK pathway play roles in GnRH gene regulation.Abstract: Gonadotropin-releasing hormone (GnRH) regulates the synthesis and secretion of follicle-stimulating hormone (FSH) by stimulating the transcription of Fshβ gene. Our iTRAQ quantitative proteomics result showed that the abundance of α-actinin4 (ACTN4) increased in the nuclei of LβT2 cells upon GnRH induction. Using RNA interference, reverse transcription and real-time PCR, luciferase and transient transfection assays, we proved that ACTN4 is involved in the regulation of mouse Fshβ gene (mFshβ) transcription and its C-terminal calmodulin (CaM)-like domain is crucial for this process. Our study suggests that ACTN4 nuclear translocation mediates GnRH stimulation of mFshβ gene transcription.α-Actinin4 nuclear translocation mediates gonadotropin-releasing hormone stimulation of follicle-stimulating hormone β-subunit gene transcription in LβT2 cellsHan Yu, Zhengjun Li, Dipanjana Ghosh, Teck Kwang Lim, Yuehui He, Qingsong Lin10.1016/j.febslet.2012.03.067FEBS Letters 586, 10 (2012)2012-04-20FEBS Letters2012-04-2058610S0014-5793(12)X0010-3Research Letters14661471http://www.febsletters.org/article/PIIS0014579312002785/abstract?rss=yesHighlights: ► miR-26 is suppressed upon ligand activation of LXRs. ► miR-26 can target ABCA1 and ARL7. ► miR-26 inhibits cholesterol efflux.Abstract: Cellular cholesterol levels are tightly regulated and represent a balance of cholesterol uptake, endogenous synthesis and efflux. Although the classic transcriptional regulations of cholesterol metabolism by liver X receptors (LXRs) have been well studied, the potential effects of LXR-responsive microRNAs (miRNAs) still need to be unveiled. Here, we describe that miR-26, an LXR-suppressed miRNA, inhibits the expression of the ATP-binding cassette transporter A1 (ABCA1) and ADP-ribosylation factor-like 7 (ARL7), two LXR target genes which play critical roles in cholesterol efflux. These findings have not only figured out an alternative mechanism for LXR regulation, but also provided a potential therapeutic target for cholesterol metabolic disorders.MiR-26 controls LXR-dependent cholesterol efflux by targeting ABCA1 and ARL7Dongsheng Sun, Jun Zhang, Jianhong Xie, Wei Wei, Mantao Chen, Xiang Zhao10.1016/j.febslet.2012.03.068FEBS Letters 586, 10 (2012)2012-04-19FEBS Letters2012-04-1958610S0014-5793(12)X0010-3Research Letters14721479http://www.febsletters.org/article/PIIS0014579312002797/abstract?rss=yesHighlights: ► CRSBP-1 ligands induce opening of lymphatic intercellular junctions. ► We examine the mechanism by which CRSBP-1 ligands exert such activity. ► CRSBP-1 is localized to the plasma membrane and ER network in endothelial cells. ► CRSBP-1 ligands stimulate contraction of the ER network in a Taxol-sensitive manner. ► Ligand-induced ER contraction is associated with ligand-induced cell contraction.Abstract: CRSBP-l/LYVE-1 ligands (PDGF-BB, VEGF-A165 and hyaluronic acid) have been shown to induce opening of lymphatic intercellular junctions in vitro and in vivo by stimulating contraction of lymphatic endothelial cells (LECs). The mechanism by which CRSBP-1 ligands stimulate contraction of LECs is not understood. Here we demonstrate that CRSBP-1 is localized to the plasma membrane as well as intracellular fibrillar structures in LECs, including primary human dermal LECs and SVEC4-10 cells. CRSBP-1-associated fibrillar structures are identical to the ER network as evidenced by the co-localization of CRSBP-1 and BiP in these cells. CRSBP-1 ligands stimulate contraction of the ER network in a CRSBP-1-dependent and paclitaxel (a microtubule-stabilizing agent)-sensitive manner. These results suggest that ligand-stimulated ER contraction is associated with ligand-stimulated contraction in LECs.CRSBP-1/LYVE-1 ligands stimulate contraction of the CRSBP-1-associated ER network in lymphatic endothelial cellsWei-Hsien Hou, I-Hua Liua, Shuan Shian Huang, Jung San Huang10.1016/j.febslet.2012.04.001FEBS Letters 586, 10 (2012)2012-04-19FEBS Letters2012-04-1958610S0014-5793(12)X0010-3Research Letters14801487http://www.febsletters.org/article/PIIS0014579312002815/abstract?rss=yesHighlights: ► Galactinol synthase (GolS) represents a monospecific clade among the GT8 (Glycosyltransferase 8) enzymes. ► The 3-D structure of GolS shows a high structural flexibility which is significant in its evolution. ► GolS has evolved primarily as a plant-specific enzyme with a probable fungal ancestry. ► Expression of GolS is linked with abiotic stress.Abstract: Galactinol synthase (GolS), a GT8 family glycosyltransferase, synthesizes galactinol and raffinose series of oligosaccharides (RFOs). Identification and analysis of conserved domains in GTs among evolutionarily diverse taxa, structure prediction by homology modeling and determination of substrate binding pocket followed by phylogenetic analysis of GolS sequences establish presence of functional GolS predominantly in higher plants, fungi having the closest possible ancestral sequences. Evolutionary preference for a functional GolS expression in higher plants might have arisen in response to the need for galactinol and RFO synthesis to combat abiotic stress, in contrast to other organisms lacking functional GolS for such functions.Galactinol synthase across evolutionary diverse taxa: Functional preference for higher plants?Sonali Sengupta, Sritama Mukherjee, Sabiha Parween, Arun Lahiri Majumder10.1016/j.febslet.2012.04.003FEBS Letters 586, 10 (2012)2012-04-13FEBS Letters2012-04-1358610S0014-5793(12)X0010-3Research Letters14881496http://www.febsletters.org/article/PIIS0014579312002839/abstract?rss=yesHighlights: ► NLK is highly expressed in testes and may be involved in spermatogenesis. ► NLK mainly localizes in the acrosomes of elongated spermatids. ► The distribution of NLK exhibits a dynamic change during testicular development. ► NLK promotes etoposide-induced apoptosis of spermatogonia-derived GC-1 cells.Abstract: Spermatogenesis is an extremely intricate process that is tightly regulated and orchestrated by a series of well-coordinated gene expression programmes. Nemo-like kinase (NLK) is an evolutionarily conserved serine/threonine kinase that functions in a wide variety of developmental events. Nevertheless, the function of NLK in spermatogenesis has not been investigated. In this study, we found that the distribution of NLK in mice exhibited a dynamic change during testicular development and gradually became concentrated in the acrosomes of elongated spermatids. NLK overexpression promoted etoposide-induced apoptosis of male germ cell-derived GC-1 cells, while knockdown of NLK by RNA interference (RNAi) attenuated etoposide-induced apoptosis. Our findings suggest that NLK plays an important role in etoposide-induced germ cell apoptosis and may be associated with spermatogenesis.Nemo-like kinase promotes etoposide-induced apoptosis of male germ cell-derived GC-1 cells in vitroXiaowen Cheng, Junbo Liang, Yu Teng, Jun Fu, Shiying Miao, Shudong Zong, Linfang Wang10.1016/j.febslet.2012.04.005FEBS Letters 586, 10 (2012)2012-04-19FEBS Letters2012-04-1958610S0014-5793(12)X0010-3Research Letters14971503http://www.febsletters.org/article/PIIS0014579312002852/abstract?rss=yesHighlights: ► Glybenclamide is an orally active K-channel blocker widely used for type II diabetes. ► It was found to inhibit PDGF-mediated cellular invasion in ovarian carcinoma cells. ► Thus, K-channel activity is likely to be a new target of anti-metastasis agent.Abstract: It has been demonstrated that potassium channels (K+ channels) play significant roles in some malignant phenotypes. Here, we provide the first evidence that treatment with glybenclamide, an ATP-sensitive K+ channel blocker, inhibited cell migration in an ovarian clear cell carcinoma cell line, ES-2. Treatment with glybenclamide or knockdown by siRNA targeted against K+ channel subunits demonstrated the suppression of ovarian cancer cell invasion, which occurred via inhibition of PDGF-AA secretion. Therefore, our findings suggest that K+ channel blockers may be useful chemotherapeutic drugs for blocking the invasiveness of ovarian cancers.Suppression of cellular invasion by glybenclamide through inhibited secretion of platelet-derived growth factor in ovarian clear cell carcinoma ES-2 cellsTamami Yasukagawa, Yuki Niwa, Siro Simizu, Kazuo Umezawa10.1016/j.febslet.2012.04.007FEBS Letters 586, 10 (2012)2012-04-25FEBS Letters2012-04-2558610S0014-5793(12)X0010-3Research Letters15041509http://www.febsletters.org/article/PIIS0014579312002876/abstract?rss=yesHighlights: ► Knockdown of pVHL decreases lung cancer cell proliferation and colonization. ► Knockdown of pVHL promotes lung cancer cell epithelial-mesenchymal transition,migration, and invasion. ► Knockdown of pVHL decreases integrin/FAK signaling in lung cancer cells.Abstract: Although von Hippel–Lindau protein (pVHL) is known as a tumor suppressor in kidney and other organs, it remains unclear whether pVHL plays a role in lung cancer development. We investigated the role of pVHL in lung cancer cell proliferation, migration, and colonization using stable A549 cells with knockdown of pVHL. We found that knockdown of pVHL promotes epithelial-mesenchymal transition (EMT) in lung cancer cells. Knockdown of pVHL decreased tumor colonization in a tail-vein injection model and decreased cell proliferation, whereas overexpression of constitutive active HIF increased tumor colonization, suggesting a HIF-independent function of pVHL in lung. Knockdown of pVHL decreased phosphorylation of FAK and expression of integrin, suggesting that pVHL regulates lung cancer development via integrin/FAK signaling pathway.Knockdown of von Hippel–Lindau protein decreases lung cancer cell proliferation and colonizationQiyuan Zhou, Tianji Chen, Joyce Christina F. Ibe, J. Usha Raj, Guofei Zhou10.1016/j.febslet.2012.04.009FEBS Letters 586, 10 (2012)2012-04-19FEBS Letters2012-04-1958610S0014-5793(12)X0010-3Research Letters15101515http://www.febsletters.org/article/PIIS0014579312002888/abstract?rss=yesHighlights: ► We identified the signal sequence and its flanking region for human LRIT3. ► LRIT3 facilitates maturation of FGFR1. ► LRIT3 modulates the PLC-γ branch of the FGFR-signaling pathway. ► FNIII and TM domains of LRIT3 can influence FGFR1-signaling.Abstract: Fibroblast growth factor receptors (FGFRs) play critical roles in craniofacial and skeletal development via multiple signaling pathways including MAPK, PI3K/AKT, and PLC-γ. FGFR-mediated signaling is modulated by several regulators. Proteins with leucine-rich repeat (LRR) and/or immunoglobulin (IG) superfamily domains have been suggested to interact with FGFRs. In addition, fibronectin leucine-rich repeat transmembrane protein 3 (FLRT3) has been shown to modulate the FGFR-mediated signaling via the fibronectin type III (FNIII) domain. Therefore proteins with LRR, IG, and FNIII are candidate regulators of the FGFRs. Here we identify leucine-rich repeat, immunoglobulin-like and transmembrane domain 3 (LRIT3) as a regulator of the FGFRs.Leucine-rich repeat, immunoglobulin-like and transmembrane domain 3 (LRIT3) is a modulator of FGFR1Sun-Don Kim, Jia Lie Liu, Tony Roscioli, Michael F. Buckley, Garima Yagnik, Simeon A. Boyadjiev, Jinoh Kim10.1016/j.febslet.2012.04.010FEBS Letters 586, 10 (2012)2012-04-20FEBS Letters2012-04-2058610S0014-5793(12)X0010-3Research Letters15161521http://www.febsletters.org/article/PIIS001457931200289X/abstract?rss=yesHighlights: ► Generation of uba3 and pcu1 temperature-sensitive mutants. ► Deletion of NEDD8 specific ligase, dcn1. ► The activity of Cullin-RING-Ligase activity and varying levels of neddylation were studied. ► Levels of Cullin neddylation did not directly correlate with activity. ► Constitutively active Pcu1p mutants could not rescue lethality from loss of neddylation.Abstract: In fission yeast, the only known essential function of Ned8p is the modification of the cullin, Pcu1p, and subsequent Cullin-RING-Ligase (CRL) activation and substrate ubiquitination. We show here that a functional Pcu1p mutant, deleted for its C-terminal autoinhibitory domain, which negates the requirement of neddylation for ligase activity, is unable to rescue the loss of neddylation. These findings suggest that the neddylation of non-cullin substrate(s) are required for Schizosaccharomyces pombe viability.Constitutively active Cullin-RING-Ligases fail to rescue loss of NEDD8 conjugation in Schizosaccharomyces pombeDavid Girdwood, Morag Robertson, Colin Gordon10.1016/j.febslet.2012.04.011FEBS Letters 586, 10 (2012)2012-04-23FEBS Letters2012-04-2358610S0014-5793(12)X0010-3Research Letters15221528http://www.febsletters.org/article/PIIS0014579312002918/abstract?rss=yesHighlights: ► We designed a structured DNA, LidNA, that significantly inhibits miRNA. ► The inhibitory effects of LidNA are superior to LNA and 2′-O-Me-RNA inhibitors. ► The miRNA binding site between double stranded regions is required for miRNA inhibition. ► The affinity of LidNA-type DNA to miRNA is over 1000 times higher than that of ssDNA. ► LidNA has higher ka and kd values than LNA and 2′-O-Me-RNA.Abstract: Many miRNA inhibitors have been developed and they are chemically modified oligonucleotides such as 2′-O-methylated RNA and locked nucleic acid (LNA). Unmodified DNA was not yet reported as a miRNA inhibitor because of the low affinity of DNA/miRNA compared to mRNA/miRNA. We designed a structured unmodified DNA that significantly inhibits miRNA function. The clue structure for activity is the miRNA binding site between double stranded regions which is responsible for the miRNA inhibitory activity and tight binding to miRNA. We developed the miRNA inhibitor constructed with unmodified DNA, and named it LidNA, DNA that puts a lid on miRNA function.LidNA, a novel miRNA inhibitor constructed with unmodified DNAAkira Tachibana, Yui Yamada, Hiroyuki Ida, Satoshi Saito, Toshizumi Tanabe10.1016/j.febslet.2012.04.013FEBS Letters 586, 10 (2012)2012-04-20FEBS Letters2012-04-2058610S0014-5793(12)X0010-3Research Letters15291532http://www.febsletters.org/article/PIIS0014579312003067/abstract?rss=yesHighlights: ► Grb7 binds calmodulin (CaM). ► Deletion of the CaM-binding domain (CaM-BD) of Grb7 prevents nuclear entry. ► Inhibition of CaM facilitates Grb7 entry into the nucleus. ► The SH2 domain of Grb7 participates in the translocation process. ► CaM controls Grb7 nuclear translocation.Abstract: We describe in this report the presence of a nuclear localization signal (NLS) overlapping the calmodulin-binding domain (CaM-BD) of the growth factor receptor bound protein 7 (Grb7). We show that deletion of the CaM-BD of Grb7 prevents its nuclear localization, and that its Src homology 2 (SH2) domain might participate as well in the translocation process. Also, treating cells with the CaM antagonist N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) enhances the presence of Grb7 in the nucleus. We propose that CaM inhibits the translocation of Grb7 to the nucleus after binding to its CaM-BD and therefore occluding its overlapping NLS.Calmodulin regulates the translocation of Grb7 into the nucleusIrene García-Palmero, Antonio Villalobo10.1016/j.febslet.2012.04.017FEBS Letters 586, 10 (2012)2012-04-26FEBS Letters2012-04-2658610S0014-5793(12)X0010-3Research Letters15331539http://www.febsletters.org/article/PIIS0014579312003079/abstract?rss=yesHighlights: ► LPS induces cxcl10, 13, and ccl5 expressions through the MyD88-independent pathway. ► MyD88 is required for the LPS-induced expression of ccl2, 7, 8, cxcl2, 3, and 9. ► Cot/Tpl2-ERK axis is inhibitory to the LPS-induced expression of ccl8 and cxcl9. ► LPS induces multiple chemokine expressions through various pathways in macrophages.Abstract: LPS signaling is mediated through MyD88-dependent and -independent pathways, activating NF-κB, MAP kinases and IRF3. Cot/Tpl2 is an essential upstream kinase in LPS-mediated activation of ERKs. Here we explore the roles of MyD88 and Cot/Tpl2 in LPS-induced chemokine expression by studying myd88−/− and cot/tpl2−/− macrophages. Among the nine LPS-responsive chemokines examined, mRNA induction of ccl5, cxcl10, and cxcl13 is mediated through the MyD88-independent pathway. Notably, Cot/Tpl2-ERK signaling axis exerts negative effects on the expression of these three chemokines. In contrast, LPS-induced gene expression of ccl2, ccl7, cxcl2, cxcl3, ccl8, and cxcl9 is mediated in the MyD88-dependent manner. The Cot/Tpl2-ERK axis promotes the expression of the first four and inhibits the expression of the latter two. Thus, LPS induces expression of multiple chemokines through various signaling pathways in macrophages.LPS-induced chemokine expression in both MyD88-dependent and -independent manners is regulated by Cot/Tpl2-ERK axis in macrophagesKenjiro Bandow, Joji Kusuyama, Mitsuo Shamoto, Kyoko Kakimoto, Tomokazu Ohnishi, Tetsuya Matsuguchi10.1016/j.febslet.2012.04.018FEBS Letters 586, 10 (2012)2012-04-23FEBS Letters2012-04-2358610S0014-5793(12)X0010-3Research Letters15401546http://www.febsletters.org/article/PIIS0014579312003109/abstract?rss=yesHighlights: ► SCFAs increase NE release from primary-cultured sympathetic neurons via GPR41. ► Sympathetic activation by SCFA involves Gβγ, PLCβ3, ERK1/2, and synapsin 2. ► Synapsin 2 directly interacts with activated ERK1/2. ► Synapsin 2b can be phosphorylated when SCFA activates sympathetic neurons.Abstract: Synapsins are neuronal phosphoproteins that coat synaptic vesicles and are believed to function in the regulation of neurotransmitter release. The signaling mechanism for short-chain free fatty acid (SCFA)-stimulated NE release was examined using primary-cultured mouse sympathetic cervical ganglion neurons. Pharmacological and knockdown experiments showed that activation of sympathetic neurons by SCFA propionate involves SCFA receptor GPR41 linking to Gβγ-PLCβ3-ERK1/2-synapsin 2 signaling. Further, synapsin 2b directly interacts with activated ERK1/2 and can be phosphorylated on serine when SCFA activates sympathetic neurons.Short-chain fatty acid receptor GPR41-mediated activation of sympathetic neurons involves synapsin 2b phosphorylationDaisuke Inoue, Ikuo Kimura, Masaki Wakabayashi, Hiroki Tsumoto, Kentaro Ozawa, Takafumi Hara, Yoshinori Takei, Akira Hirasawa, Yasushi Ishihama, Gozoh Tsujimoto10.1016/j.febslet.2012.04.021FEBS Letters 586, 10 (2012)2012-04-23FEBS Letters2012-04-2358610S0014-5793(12)X0010-3Research Letters15471554http://www.febsletters.org/article/PIIS0014579312003110/abstract?rss=yesHighlights: ► Phospholipase C overexpression causes repression of UASino containing genes. ► Phospholipid metabolism can be regulated by phospholipase C. ► Regulation through phospholipase C appears to represent an overall regulation of lipid metabolism.Abstract: The regulation of phospholipid biosynthesis in Saccharomyces cerevisiae through cis-acting upstream activating sequence inositol (UASino) and trans-acting elements, such as the INO2–INO4 complex and OPI1 by inositol supplementation in growth is thoroughly studied. In this study, we provide evidence for the regulation of lipid biosynthesis by phosphatidylinositol-specific phospholipase C (PLC) through UASino and the trans-acting elements. Gene expression analysis and radiolabelling experiments demonstrated that the overexpression of rice PLC in yeast cells altered phospholipid biosynthesis at the levels of transcriptional and enzyme activity. This is the first report implicating PLC in the direct regulation of lipid biosynthesis.Regulation of lipid biosynthesis by phosphatidylinositol-specific phospholipase C through the transcriptional repression of upstream activating sequence inositol containing genesSunny D. Rupwate, Preeti S. Rupwate, Ram Rajasekharan10.1016/j.febslet.2012.04.022FEBS Letters 586, 10 (2012)2012-04-23FEBS Letters2012-04-2358610S0014-5793(12)X0010-3Research Letters15551560