REGULATORY REGIONS IN THE PROMOTERS OF THE SACCHAROMYCES-CEREVISIAE PYC1 AND PYC2 GENES ENCODING ISOENZYMES OF PYRUVATE-CARBOXYLASE

We have identified regions in the promoters of the PYC1 and PYC2 genes from Saccharomyces cerevisiae involved in their regulation in differe nt culture conditions. In the case of PYC1, a UAS in the region betwee n -330/-297 and three repressing sequences with the common central cor e CCGCC at positions -457, -432 and -399 were identified. Specific bin ding of nuclear proteins to the -330/-214 DNA fragment was abolished i n rtg mutants suggesting a role for the RTG genes in the control of PY C1 expression. In the case of the PYC2 promoter, elimination of a frag ment from -417 to -291 brings about a two-fold decrease in the express ion in repressed conditions and a similar increase in derepression. (C ) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.