What does the MIG1 protein do?
What does the MIG1 protein do?
Mig1 is a zinc finger protein that mediates glucose repression in the yeast Saccharomyces cerevisiae. It is related to the mammalian Krox/Egr, Wilms’ tumor, and Sp1 proteins and binds to a GC-rich motif that resembles the GC boxes recognized by these proteins.
Why is MIG1 protein good for yeast?
MIG1 protein binds to two sites in the upstream region of SUC2, a yeast gene that is repressed by glucose. Thus, finger proteins that are similar in both amino acid sequence and DNA specificity are involved in the response of yeast to glucose, and in the mammalian early growth response.
Why is MIG1 important?
Mig1p, a zinc finger DNA-binding protein, is the main involved component that mediates glucose induced repression of sugars. Inactivation of MIG1 gene derepresses the expression of invertase encoded by SUC2 9. Snf1 kinase regulates glucose derepression of genes required for utilization of alternative carbon sources.
How does the environment from yeast come affect their ability to metabolise galactose?
If both sugars are present, the yeast will first metabolize glucose, depleting it from the extracellular environment. Paradoxically, we find that Gal1p, an enzyme needed for galactose metabolism, accumulates more quickly if glucose is depleted slowly rather than taken away quickly.
What is MIG1?
MIG1 was first identified as a Multicopy Inhibitor of Galactose gene expression (1). Mig1p is a Zinc-finger protein, of the Cys2His2 type, that binds specifically to DNA with a GC-rich consensus sequence and a flanking AT sequence (3).
What does SNF1 stand for?
The SNF1 (sucrose non-fermenting 1)-related protein kinases 1 (SnRKs1) are the plant orthologs of the budding yeast SNF1 and mammalian AMPK (AMP-activated protein kinase). These evolutionarily conserved kinases are metabolic sensors that undergo activation in response to declining energy levels.
Is MIG1 a repressor?
Repression by SSN6-TUP1 is directed by MIG1, a repressor/activator protein.
How is SNF1 activated?
In yeast, the AMP-activated protein kinase, called Snf1, is activated when energy and nutrients are scarce. Earlier studies have demonstrated that activation of Snf1 requires the phosphorylation of the activation loop on threonine 210.
What is the function of the mig1p gene?
It is thought that a major function of Mig1p is to repress the transcription of genes whose expression is shut off when glucose is present, such as those encoding enzymes for utilization of the sugars maltose, sucrose, or galactose ( 8, 2 ).
How is MIG1 related to the early growth response?
Nehlin JO and Ronne H (1990) Yeast MIG1 repressor is related to the mammalian early growth response and Wilms’ tumour finger proteins. EMBO J 9 (9):2891-8 PMID: 2167835
Where does mig1p go after phosphorylation?
When cells become limited for glucose, Mig1p is phosphorylated by the Snf1 kinase complex, composed of the Snf1 kinase catalytic subunit, the gamma subunit Snf4p, and a beta subunit encoded by SIP1, SIP2, or GAL83 ( 4 ). Upon phosphorylation, Mig1p is exported from the nucleus by the nuclear exportin Msn5p ( 2 ).