A Novel Downstream Regulatory Element Cooperates with the Silencing Machinery to Repress EPA1 Expression in Candida glabrata

作者：Gallegos Garcia Veronica; Pan Shih Jung; Juarez Cepeda Jacqueline; Ramirez Zavaleta Candy Y; Briones Martin del Campo Marcela; Martinez Jimenez Veronica; Castano Irene; Cormack Brendan; De Las Penas Alejandro^*

来源：Genetics, 2012, 190(4): 1285-1297.

DOI：10.1534/genetics.111.138099

Candida glabrata, an opportunistic fungal pathogen, adheres to mammalian epithelial cells; adherence is mediated primarily by the Epa1 adhesin. EPA1 is a member of a large gene family of similar to 23 paralogues, which encode putative adhesins. In this study, we address how EPA1 transcription is regulated. Our data show that EPA1 expression is subject to two distinct negative regulatory mechanisms. EPA1 transcription is repressed by subtelomeric silencing: the Sir complex (Sir2-Sir4), Rap1, Rif1, yKu70, and yKu80 are required for full repression. Activation of EPA1 occurs immediately after dilution of stationary phase (SP) cells into fresh media; however, transcription is rapidly repressed again, limiting expression to lag phase, just as the cells exit stationary phase. This repression following lag phase requires a cis-acting regulatory negative element (NE) located in the EPA1 3'-intergenic region and is independent of telomere proximity. Bioinformatic analysis shows that there are 10 copies of the NE-like sequence in the C. glabrata genome associated with other EPA genes as well as non-EPA genes.

• 出版日期2012-4