Regulation of the expression of the Kluyveromyces lactis PDC1 gene: Carbonsource-responsive elements and autoregulation

The yeast Kluyveromyces lactis has a single structural gene coding for pyru vate decarboxylase (KlPDC1). In order to study the regulation of the expres sion of KlPDC1, we have sequenced (EMBL Accession No. Y15435) its promoter and have fused the promoter to the reporter gene lacZ from E. coli. Transcr iption analysis in a Klpdc1 Delta strain showed that KlPDC1 expression is s ubject to autoregulation. The PDC1 gene from Saccharomyces cerevisiae was a ble to complement the Rag(-) phenotype of the Klpdc1 Delta mutant strain an d it could also repress transcription of the KlPDC1-lacZ fusion on glucose. A deletion analysis of the promoter region was performed to study carbon s ource-dependent regulation and revealed that at least two cis-acting region s are necessary for full induction of gene expression on glucose. Other cis -elements mediate repression on ethanol. Copyright (C) 1999 John Wiley & So ns, Ltd.