Differential control of isocitrate lyase gene transcription by non-fermentable carbon sources in the milk yeast Kluyveromyces lactis

Rodicio, Rosaura; López, Maria Luz; Cuadrado, Sara; Cid, Alejandra F.; Redruello, Begoña; Moreno, Fernando; Heinisch, Jürgen J.; Hegewald, Anne-Kathrin; Breunig, Karin D.

doi:10.1016/j.febslet.2008.01.017

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Volume 582, Issue 5 , Pages 549-557, 5 March 2008

Differential control of isocitrate lyase gene transcription by non-fermentable carbon sources in the milk yeast Kluyveromyces lactis

Edited by Ivan Sadowski

Rosaura Rodicio
- Departamento de Bioquímica y Biología Molecular and Instituto Universitario de Biotecnología de Asturias, Facultad de Medicina, Universidad de Oviedo, Campus del Cristo, 33006 Oviedo, Spain
- Corresponding author. Fax: +34 985 103157.
Maria Luz López
- Departamento de Bioquímica y Biología Molecular and Instituto Universitario de Biotecnología de Asturias, Facultad de Medicina, Universidad de Oviedo, Campus del Cristo, 33006 Oviedo, Spain
Sara Cuadrado
- Departamento de Bioquímica y Biología Molecular and Instituto Universitario de Biotecnología de Asturias, Facultad de Medicina, Universidad de Oviedo, Campus del Cristo, 33006 Oviedo, Spain
Alejandra F. Cid
- Departamento de Bioquímica y Biología Molecular and Instituto Universitario de Biotecnología de Asturias, Facultad de Medicina, Universidad de Oviedo, Campus del Cristo, 33006 Oviedo, Spain
Begoña Redruello
- Departamento de Bioquímica y Biología Molecular and Instituto Universitario de Biotecnología de Asturias, Facultad de Medicina, Universidad de Oviedo, Campus del Cristo, 33006 Oviedo, Spain
Fernando Moreno
- Departamento de Bioquímica y Biología Molecular and Instituto Universitario de Biotecnología de Asturias, Facultad de Medicina, Universidad de Oviedo, Campus del Cristo, 33006 Oviedo, Spain
Jürgen J. Heinisch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastrasse 11, D-49076 Osnabrück, Germany
Anne-Kathrin Hegewald
- Martin-Luther-Universität Halle-Wittenberg, Institut für Biologie/Genetik, D-06099 Halle, Germany
Karin D. Breunig
- Martin-Luther-Universität Halle-Wittenberg, Institut für Biologie/Genetik, D-06099 Halle, Germany

Received 8 October 2007; received in revised form 15 January 2008; accepted 18 January 2008. published online 31 January 2008.

Abstract

The KlICL1 gene, encoding isocitrate lyase in Kluyveromyces lactis, is essential for ethanol utilization. Deletion analyses identified two functional promoter elements, CSRE-A and CSRE-B. Transcription is activated on ethanol, but not on glucose, glycerol or lactate. Expression depends on the KlCat8p transcription factor and KlSip4p binds to the promoter elements. Glycerol diminishes KlICL1 expression and a single carbon source responsive element (CSRE) sequence is both necessary and sufficient to mediate this regulation. The glycerol effect is less pronounced in Saccharomyces cerevisiae than in K. lactis. Mutants lacking KlGUT2 (which encodes the glycerol 3-phosphate dehydrogenase) still show reduced expression in glycerol, whereas mutants deficient in glycerol kinase (Klgut1) do not. We conclude that a metabolite of glycerol is required for this regulation.

Abbreviations: CSRE, carbon source responsive element, nt, nucleotide, PCR, polymerase chain reaction

Keywords: Ethanol metabolism, Isocitrate lyase, Carbon source responsive element, CAT8, SIP4, Yeast