Elble R, Tye B K
Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853.
Proc Natl Acad Sci U S A. 1991 Dec 1;88(23):10966-70. doi: 10.1073/pnas.88.23.10966.
Mcm1 is a yeast transcription factor with homologs throughout the metazoa. MCM1 was first identified as a gene involved in maintenance of artificial minichromosomes in yeast. More recently Mcm1 has been shown to serve as a transcriptional regulator of mating-type-specific genes. Biochemical data suggest that Mcm1 coactivates alpha-specific genes and corepresses a-specific genes by binding to a 10-base-pair dyad symmetry element in their upstream regions. We reported previously that an mcm1 point mutation reduced activation of alpha-specific genes but had little effect on the expression of a-specific genes. We now show that another mcm1 allele, which depletes the Mcm1 protein, affects both activation and repression of a-specific genes. The mutant strain remains capable of high levels of pheromone induction of a-specific genes, although with retarded kinetics. Mcm1 joins an increasing number of transcription factors involved in both positive and negative regulation of gene expression.
Mcm1是一种酵母转录因子，在整个后生动物中都有同源物。MCM1最初被鉴定为参与酵母人工微型染色体维持的基因。最近，Mcm1已被证明可作为交配型特异性基因的转录调节因子。生化数据表明，Mcm1通过与α特异性基因上游区域的10个碱基对的二元对称元件结合来共激活α特异性基因并抑制a特异性基因。我们之前报道过，mcm1点突变会降低α特异性基因的激活，但对a特异性基因的表达影响很小。我们现在表明，另一个耗尽Mcm1蛋白的mcm1等位基因会影响a特异性基因的激活和抑制。突变菌株仍然能够高水平地诱导a特异性基因的信息素，尽管动力学有所延迟。Mcm1加入了越来越多参与基因表达正负调控的转录因子行列。
