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SIP1 is a catabolite repression-specific negative regulator of GAL gene expression. Genetics 1994 Jul;137(3):689-700



Pubmed ID


Pubmed Central ID




Scopus ID

2-s2.0-0028338673 (requires institutional sign-in at Scopus site)   10 Citations


The yeast Snf1p kinase is required for normal expression of many genes involved in utilization of non-glucose carbon. Snf1p is known to associate with several proteins. One is Sip1p, a protein that becomes phosphorylated in the presence of Snf1p and thus is a candidate Snf1p kinase substrate. We have isolated the SIP1 gene as a multicopy suppressor of the gal83-associated defect in glucose repression of GAL gene expression. Multicopy SIP1 also suppressed the gal82-associated defect in glucose repression, suggesting that SIP1, GAL83 and GAL82 function interdependently. Multicopy SIP1 gene reduces GAL1, GAL2, GAL7 and GAL10 gene expression three- to fourfold in cells grown in the presence of glucose but has no effect in cells grown on nonrepressing carbon. Sip1-deletion cells exhibited a two- to threefold increase in GAL gene expression compared to wild-type cells when grown on glucose. These studies show that SIP1 is a catabolite repression-specific negative regulator of GAL gene expression. Northern analysis revealed two SIP1 transcripts whose relative abundance changed with carbon source. Western blots revealed that Sip1p abundance is not markedly affected by carbon source, suggesting that Sip1p may be regulated post-translationally.

Author List

Mylin LM, Bushman VL, Long RM, Yu X, Lebo CM, Blank TE, Hopper JE


Roy M. Long PhD Assistant Dean, Associate Professor in the Medical School Regional Campuses department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

AMP-Activated Protein Kinases
Base Sequence
Carrier Proteins
Enzyme Repression
Fungal Proteins
Gene Deletion
Gene Expression Regulation, Fungal
Genes, Fungal
Genes, Suppressor
Molecular Sequence Data
Multigene Family
Protein Kinases
Repressor Proteins
Restriction Mapping
Saccharomyces cerevisiae
Saccharomyces cerevisiae Proteins
Signal Transduction
Substrate Specificity
Transcription Factors