Repression by SSN6-TUP1 is directed by MIG1, a repressor/activator protein

• Published in: Proceedings of the National Academy of Sciences - PNAS 1995-04, Vol.92 (8), p.3132-3136
• Main Authors: Treitel, M.A. (Columbia University, New York, NY.), Carlson, M
• Format: Article
• Language: English
• Subjects: ADN; Bacterial Proteins - genetics; Base Sequence; Binding sites; Cells; Cellular biology; DNA; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; FOSFORILACION; Fungal Proteins - genetics; Fungal Proteins - metabolism; Gene Expression Regulation, Fungal; Genes; Genetic mutation; Genetics; Glucose - metabolism; Medical genetics; Models, Genetic; Molecular Sequence Data; Nuclear Proteins; Phosphatases; PHOSPHORYLATION; Plasmids; Protein Binding; PROTEINAS; PROTEINAS AGLUTINANTES; PROTEINE; PROTEINE DE LIAISON; Proteins; Recombinant Fusion Proteins - metabolism; Repression; Repressor Proteins; SACCHAROMYCES CEREVISIAE; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae Proteins; Serine Endopeptidases; Transcription, Genetic; Yeast
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.92.8.3132

The SSN6-TUP1 protein complex represses transcription of diversely regulated genes in the yeast Saccharomyces cerevisiae. Here we present evidence that MIG1, a zinc-finger protein in the EGR1/Zif268 family, recruits SSN6-TUP1 to glucose-repressed promoters. DNA-bound LexA-MIG1 represses transcription of a target gene in glucose-grown cells, and repression requires SSN6 and TUP1. We also show that MIG1 and SSN6 fusion proteins interact in the two-hybrid system. Unexpectedly, we found that LexA-MIG1 activates transcription strongly in an ssn6 mutant and weakly in a tup1 mutant. Finally, LexA-MIG1 does not repress transcription in glucose-deprived cells, and MIG1 is differentially phosphorylated in response to glucose availability. We suggest a role for phosphorylation in regulating repression.