Molecular and General Genetics MGG

, Volume 262, Issue 4, pp 869–875

Cat8p, the activator of gluconeogenic genes in Saccharomyces cerevisiae, regulates carbon source-dependent expression of NADP-dependent cytosolic isocitrate dehydrogenase (Idp2p) and lactate permease (Jen1p)

  • N. Bojunga
  • K.-D. Entian
ORIGINAL PAPER

DOI: 10.1007/s004380051152

Cite this article as:
Bojunga, N. & Entian, KD. Mol Gen Genet (1999) 262: 869. doi:10.1007/s004380051152

Abstract

The yeast transcriptional activator Cat8p has been identified as a factor that is essential for the derepression of genes involved in gluconeogenesis (like FBP1, PCK1, ACR1, ICL1 and MLS1) when only non-fermentable carbon sources are provided. Cat8p-dependent expression is mediated by cis-acting elements in the respective promoters, which are named UAS/CSREs (upstream activating sequence/carbon source responsive element). To establish whether the function of Cat8p is restricted to the activation of gluconeogenesis or is also involved in the regulation of a greater variety of genes, we investigated the transcriptional regulation of two genes, IDP2 and JEN1, which exhibit a similar expression pattern to gluconeogenic genes, although IDP2 at least is not linked directly to the gluconeogenic pathway. We identified functional UAS/CSRE elements in the promoters of both genes. Expression studies revealed that JEN1 is regulated negatively by the repressors Mig1p and Mig2p, and that Cat8p is needed for full derepression of the gene under non-fermentative growth conditions. Furthermore, we showed that Mig2p is also involved in the repression of CAT8 itself. The results presented in this study support a model in which Cat8p-dependent gene activation is not restricted to gluconeogenesis, but targets a wide variety of genes which are strongly derepressed under non-fermentative growth conditions.

Key wordsCAT8 Transcriptional regulation IDP2 JEN1 Saccharomyces cerevisiae 

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • N. Bojunga
    • 1
  • K.-D. Entian
    • 1
  1. 1.Institut für Mikrobiologie, Johann Wolfgang Goethe-Universität, Marie-Curie-Str. 9, D-60439 Frankfurt/Main, Germany e-mail: Entian@em.uni-frankfurt.de Tel.: +69-79829525; Fax: +69-79829527DE