Identification of regulatory proteins that might be involved in carbon catabolite repression of the aminopeptidase I gene of the yeast Saccharomyces cerevisiae

Abstract

Transcription of the vacuolar aminopeptidase yscI (APE1) gene in Saccharomyces cerevisiae has previously been suggested to require the participation of a cis upstream activation sequence (UAS) involved in carbon catabolite repression that responds to glucose. To determine the structure of the APE1 UAS element, we used the 18-bp sequence 5'-ATGAAT-TAGTCAGCTTCT-3' as the DNA-binding site. Using gel mobility shift assays, we have identified a 78 kDa protein from yeast that binds specifically to both single and double-stranded forms of the UAS DNA-binding site. We have also identified a 48 kDa heterodimer from yeast that binds specifically to the singlestranded form of the UAS and whose DNA binding activity is remarkably heat stable. Even though the APE1 UAS contains a consensus sequence for the binding of the yeast activator protein yAP1, the two DNA-protein complexes could still be detected in a strain bearing a deletion in the YAP1 gene.

Biochemical characterization and structural prediction of a novel cytosolic leucyl aminopeptidase of the M17 family from Schizosaccharomyces pombe

“…4), suggesting possible transcriptional regulation of LAP yspII expression by nutrient limitation, as has been shown to be the case with several Sa. cerevisiae peptidases [8]. Even though introns are frequent in S. pombe genes [34], we could not find any consensus sequence for the presence of introns among the 2340 bp examined.…”

“…A wide collection of aminopeptidase activities have been described in the yeast Saccharomyces cerevisiae , the best characterized being vacuolar aminopeptidase I [6–8], cytosolic metallo‐aminopeptidase II [9], bleomycin hydrolase (aminopeptidase yscIII) [10], aminopeptidase Y [11], aspartyl aminopeptidase and methionyl aminopeptidase, but not one has been classified as an M17 peptidase.…”