Transcriptional regulation of nonfermentable carbon utilization in budding yeast

Authors

  • Bernard Turcotte,

    1. Department of Medicine, Royal Victoria Hospital, McGill University, Montréal, QC, Canada
    2. Department of Biochemistry, Royal Victoria Hospital, McGill University, Montréal, QC, Canada
    3. Department of Microbiology and Immunology, Royal Victoria Hospital, McGill University, Montréal, QC, Canada
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  • Xiao Bei Liang,

    1. Department of Microbiology and Immunology, Royal Victoria Hospital, McGill University, Montréal, QC, Canada
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  • François Robert,

    1. Institut de recherches cliniques de Montréal, Montréal, QC, Canada
    2. Département de Médecine, Université de Montréal, Montréal, QC, Canada
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  • Nitnipa Soontorngun

    1. Department of Biochemistry, Royal Victoria Hospital, McGill University, Montréal, QC, Canada
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  • Editor: Teun Boekhout

  • Present address: Nitnipa Soontorngun, King Mongkut's University of Technology Thonburi, School of Bioresources and Technology, Biochemical Technology, 5th floor, 83 Moo8, Tean Talay-23 Road, Tha Kham, Bang Khun Tean, Bangkok 10150, Thailand.

Correspondence: Bernard Turcotte, Department of Medicine, Room H5. 74, Royal Victoria Hospital, McGill University, 687 Pine Ave. West, Montréal, QC, Canada H3A 1A1. Tel.: +514 934 1934, ext. 35046 (or 35047); fax: +514 982 0893; e-mail: bernard.turcotte@mcgill.ca

Abstract

Saccharomyces cerevisiae preferentially uses glucose as a carbon source, but following its depletion, it can utilize a wide variety of other carbons including nonfermentable compounds such as ethanol. A shift to a nonfermentable carbon source results in massive reprogramming of gene expression including genes involved in gluconeogenesis, the glyoxylate cycle, and the tricarboxylic acid cycle. This review is aimed at describing the recent progress made toward understanding the mechanism of transcriptional regulation of genes responsible for utilization of nonfermentable carbon sources. A central player for the use of nonfermentable carbons is the Snf1 kinase, which becomes activated under low glucose levels. Snf1 phosphorylates various targets including the transcriptional repressor Mig1, resulting in its inactivation allowing derepression of gene expression. For example, the expression of CAT8, encoding a member of the zinc cluster family of transcriptional regulators, is then no longer repressed by Mig1. Cat8 becomes activated through phosphorylation by Snf1, allowing upregulation of the zinc cluster gene SIP4. These regulators control the expression of various genes including those involved in gluconeogenesis. Recent data show that another zinc cluster protein, Rds2, plays a key role in regulating genes involved in gluconeogenesis and the glyoxylate pathway. Finally, the role of additional regulators such as Adr1, Ert1, Oaf1, and Pip2 is also discussed.

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