Control of yeast GAL genes by MIG1 repressor: a transcriptional cascade in the glucose response.
Glucose repression is a global regulatory mechanism in yeast. We have investigated how glucose regulates the GAL genes, which are required for galactose fermentation. We found that the GAL genes are controlled by a transcriptional cascade. Thus, GAL4, which encodes an activator of the GAL genes, is repressed by MIG1, a zinc finger protein that binds to the GAL4 promoter. MIG1 has a dual role in control of the GAL genes, since MIG1 also binds to the promoter of GAL1, a gene regulated by GAL4. A disruption of MIG1 interacts synergistically with a disruption of GAL80, a gene involved in galactose induction. This suggests that the MIG1-dependent response to glucose is amplified by down-regulation of the induction pathway.
Nehlin
J O
JO
Ludwig Institute for Cancer Research, Biomedical Center, Uppsala, Sweden.
Carlberg
M
M
Ronne
H
H
D001483:Base Sequence; D015152:Blotting, Northern; D016172:DNA Fingerprinting; D015536:Down-Regulation; D005690:Galactose / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D016153:Genes, Suppressor; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012331:RNA, Fungal / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014158:Transcription, Genetic; D016335:Zinc Fingers / Q000187:drug effects* / Q000235:genetics
D012331:RNA, Fungal; D005690:Galactose