Repression by the yeast meiotic inhibitor RME1.
The RME1 gene product, a negative regulator of meiosis with three zinc finger motifs, acts by preventing transcript accumulation from IME1, whose product is required for meiotic gene expression. We have isolated a 404-bp segment from a region 2 kb upstream of IME1 that is sufficient for RME1-dependent repression of a heterologous promoter. This DNA contains an RME1-response element (RRE) and another region called the modulation region. The modulation region is required for repression because DNA containing the RRE alone did not repress but was able to confer RME1-dependent transcriptional activation of a reporter gene. In gel mobility retardation assays, RME1 formed a specific complex with the RRE, and RRE point mutations that reduced the affinity for RME1 also blocked repression and activation. Footprinting of the RME1-RRE complex revealed a 21-bp protected region that included the positions of these RRE mutations. We conclude that RME1 binding to this RRE is required for repression. Thus, the mechanism of meiotic inhibition by RME1 is direct transcriptional repression of IME1.
Covitz
P A
PA
Department of Microbiology, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
Mitchell
A P
AP
D001483:Base Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015536:Down-Regulation; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008540:Meiosis; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D017354:Point Mutation; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D013172:Spores, Fungal; D014158:Transcription, Genetic; D015854:Up-Regulation; D016335:Zinc Fingers
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C071594:RME1 protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins