Open AccessDosage-dependent modulation of glucose repression by MSN3 (STD1) in Saccharomyces cerevisiae.
Author(s) -
E. Jane Albert Hubbard,
Rong Jiang,
Marian Carlson
Publication year - 1994
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.14.3.1972
Subject(s) - derepression , biology , cyclin dependent kinase 7 , saccharomyces cerevisiae , psychological repression , kinase , snf3 , protein kinase a , gene , transcription factor , activator (genetics) , biochemistry , mutant , transcription (linguistics) , microbiology and biotechnology , gene expression , mitogen activated protein kinase kinase , linguistics , philosophy
The SNF1 protein kinase of Saccharomyces cerevisiae is required to relieve glucose repression of transcription. To identify components of the SNF1 pathway, we isolated multicopy suppressors of defects caused by loss of SNF4, an activator of the SNF1 kinase. Increased dosage of the MSN3 gene restored invertase expression in snf4 mutants and also relieved glucose repression in the wild type. Deletion of MSN3 caused no substantial phenotype, and we identified a homolog, MTH1, encoding a protein 61% identical to MSN3. Both are also homologous to chicken fimbrin, human plastin, and yeast SAC6 over a 43-residue region. Deletion of MSN3 and MTH1 together impaired derepression of invertase in response to glucose limitation. Finally, MSN3 physically interacts with the SNF1 protein kinase, as assayed by a two-hybrid system and by in vitro binding studies. MSN3 is the same gene as STD1, a multicopy suppressor of defects caused by overexpression of the C terminus of TATA-binding protein (R. W. Ganster, W. Shen, and M. C. Schmidt, Mol. Cell. Biol. 13:3650-3659, 1993). Taken together, these data suggest that MSN3 modulates the regulatory response to glucose and may couple the SNF1 pathway to transcription.