Effect of upstream sequences of the ADH1 promoter on the expression of Hormoconis resinae glucoamylase P by Saccharomyces cerevisiae.

The effect of the upstream sequences of the yeast ADH1 promoter on the expression of Hormoconis resinae glucoamylase P by Saccharomyces cerevisiae was studied. Sequence analysis of the 5'-terminal region of the promoter revealed sequence patterns resembling a transcription start point and the binding site for the regulatory protein ADR1. A short promoter was constructed by deleting all the promoter sequences upstream of nucleotide -409, including the upstream activating sequence UASRPG. A medium-length promoter was constructed by deleting a fragment of 558 bp containing the putative upstream transcription start point but not the UAS. The short promoter increased the glucoamylase expression level 1.6-fold compared with the long promoter, but the beginning of secretion was delayed by about 10 h probably because of the absence of the UAS. The medium-length promoter directed expression of the glucoamylase without an initial delay, with the enzyme activity lying between the activities produced under the long and short promoters. Northern blot analysis confirmed the secretion patterns of the strains with different promoters but failed to reveal any transcripts starting at the putative upstream start point.