GLC8 encodes a regulatory subunit of protein phosphatase 1 (2). Glc7p is the catalytic subunit of protein phosphatase 1, and interacts with a collection of noncatalytic regulatory subunits that modulate its subcellular localization, substrate specificity, and enzyme activity (5). Under normal conditions, Glc8p activates Glc7p, but when Glc8p is overproduced, it may also inhibit Glc7p function (6). Glc8p is required for increased Glc7p activity during stationary phase (2), and is involved in chromosome segregation (6), and to a lesser degree in glycogen accumulation (5). GLC8 is glucose repressed, and Glc8p is activated upon phosphorylation by Pho85p complexed with one of four cyclins (Pcl6p, Pcl7p, Pcl8p, or Pcl10p) (3).

Deletion of GLC8 is not lethal, but does result in a 20% reduction in glycogen accumulation compared to wild type (5). Glc8p exhibits similarity to mammalian phosphatase inhibitor-2 proteins (3).

Last updated: 2005-09-20