Human protein phosphatase PP6 regulatory subunits provide Sit4-dependent and rapamycin-sensitive sap function in Saccharomyces cerevisiae.

ABSTRACT: In the budding yeast Saccharomyces cerevisiae the protein phosphatase Sit4 and four associated proteins (Sap4, Sap155, Sap185, and Sap190) mediate G(1) to S cell cycle progression and a number of signaling events controlled by the target of rapamycin TOR signaling cascade. Sit4 and the Sap proteins are ubiquitously conserved and their human orthologs, PP6 and three PP6R proteins, share significant sequence identity with their yeast counterparts. However, relatively little is known about the functions of the PP6 and PP6R proteins in mammalian cells. Here we demonstrate that the human PP6R proteins physically interact with Sit4 when expressed in yeast cells. Remarkably, expression of PP6R2 and PP6R3 but not expression of PP6R1 rescues the growth defect and rapamycin hypersensitivity of yeast

SUBMITTER: Morales-Johansson H 

PROVIDER: S-EPMC2708350 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature