Open AccessSequences within an upstream activation site in the yeast enolase gene ENO2 modulate repression of ENO2 expression in strains carrying a null mutation in the positive regulatory gene GCR1.
Author(s) -
J P Holland,
Paul K. Brindle,
Michael J. Holland
Publication year - 1990
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.10.9.4863
Subject(s) - biology , psychological repression , gene , transcription factor , microbiology and biotechnology , null allele , binding site , genetics , mutation , dna binding site , regulation of gene expression , mutant , gene expression , dna binding protein , transcription (linguistics) , promoter , linguistics , philosophy
Transcription of the yeast enolase gene ENO2 is reduced 20- to 50-fold in strains carrying a null mutation in the positive regulatory gene GCR1. A small deletion mutation within one of two upstream activation sites (UAS elements) in the 5'-flanking region of ENO2 permitted wild-type levels of ENO2 gene expression in a strain carrying the gcr1 null mutation. These data show that sequences required for UAS element activity in GCR1 strains were required to repress ENO2 expression in a gcr1 strain. Protein factors that specifically bound to this UAS/repression site were identified. We show that the DNA-binding protein ABFI (autonomously replicating sequence-binding factor) is the major protein which binds the UAS/repression site. Minor DNA-binding activities that interact specifically with the UAS/repression site were also identified and may correspond to proteolytic breakdown products of ABFI. None of the observed binding activities were encoded by the GCR1 structural gene. A double-stranded oligonucleotide that included the UAS/repression site activated transcription of UAS-less ENO1 and ENO2 gene cassettes in vivo to wild-type levels in strains carrying the GCR1 allele as well as the gcr1 null mutation. These latter data show that the UAS/repression site is sufficient for transcriptional activation but is not sufficient to repress transcription of the enolase genes in a gcr1 genetic background.