MULTIPLE POSITIVE AND NEGATIVE CIS-ACTING ELEMENTS OF THE STA2 GENE REGULATE GLUCOAMYLASE SYNTHESIS IN SACCHAROMYCES-CEREVISIAE

Expression of the glucoamylase-encoding gene (STA2) in Saccharomyces c erevisiae was previously shown to be regulated transcriptionally by bo th positive and negative factors. The objective of this work was to id entify the cis-acting elements responsible for STA2 transcriptional ac tivation as well as the transcriptional repressor effects of STA10 and MATa/MAT alpha. We identified two upstream activation regions (UAS). Three repressor regions responsive to STA10-mediated repression were i dentified, as well as two regions for down-regulation of STA2 expressi on. MATa/MAT alpha repression appears to effect STA2 expression either downstream from the translational start site or, indirectly, since no functional a1/alpha 2responsive sequence was identified in the promot er region.