Send to

Choose Destination
Mol Cell Biol. 1995 Jun;15(6):2955-61.

Positive control of yeast meiotic genes by the negative regulator UME6.

Author information

Integrated Program in Cellular, Molecular, and Biophysical Studies, Columbia University, New York, New York 10032, USA.


The yeast meiotic activator IME1 stimulates transcription of many early meiotic genes. These genes share a 5' sequence called URS1. URS1 sites function as repression sites in cells that lack IME1; we show here that URS1 sites are weak activation sequences in cells that express IME1. Repression through URS1 sites is known to depend upon the URS1-binding protein UME6. We have identified a UME6 allele (previously called rim16-12) that causes a defect in IME1-dependent activation of meiotic genes but not in repression through URS1 sites. In contrast, a ume6 null mutation causes defects in both IME1-dependent activation and in repression through URS1 sites. A LexA-UME6 fusion protein is an IME1-dependent transcriptional activator, whereas a LexA-UME6 fusion carrying the rim16-12 substitution cannot activate transcription. These findings argue that IME1 activates meiotic genes by converting UME6 from a negative regulator to a positive regulator; the rim16-12 mutant protein is defective in conversion to a positive regulator.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center