Identification of factors involved in MSE-mediated repression of SMK1

Abstract

Meiotic development in Saccharomyces cerevisiae is carried out by temporal regulation of distinct sets of genes. We have previously shown that a promoter element called the MSE, middle sporulation element, is responsible for the timing of expression of genes during the middle stages of sporulation. The role of many MSEs is to repress transcription of middle sporulation genes during vegetative growth and to activate transcription during meiotic growth. Previous work has shown that the Sum1, Hst1, and Rfm1 proteins are required for MSE-mediated repression. Interestingly, DNA microarray expression analysis shows that Sum1 is required for repression of a large number of middle sporulation genes while Hst1 and Rfm1 are required to repress only a subset of these genes. This result suggests that Sum1 may interact with other factors to repress genes not regulated by Hst1 and Rfm1. This study tries to identify factors that may interact with Sum1 to repress transcription during vegetative growth.