title: The REG2 gene of Saccharomyces cerevisiae encodes a type 1 protein phosphatase-binding protein that functions with Reg1p and the Snf1 protein kinase to regulate growth.
abstract: The GLC7 gene of Saccharomyces cerevisiae encodes the catalytic subunit of type 1 protein phosphatase (PP1) and is essential for cell growth. We have isolated a previously uncharacterized gene, REG2, on the basis of its ability to interact with Glc7p in the two-hybrid system. Reg2p interacts with Glc7p in vivo, and epitope-tagged derivatives of Reg2p and Glc7p coimmunoprecipitate from cell extracts. The predicted protein product of the REG2 gene is similar to Reg1p, a protein believed to direct PP1 activity in the glucose repression pathway. Mutants with a deletion of reg1 display a mild slow-growth defect, while reg2 mutants exhibit a wild-type phenotype. However, mutants with deletions of both reg1 and reg2 exhibit a severe growth defect. Overexpression of REG2 complements the slow-growth defect of a reg1 mutant but does not complement defects in glycogen accumulation or glucose repression, two traits also associated with a reg1 deletion. These results indicate that REG1 has a unique role in the glucose repression pathway but acts together with REG2 to regulate some as yet uncharacterized function important for growth. The growth defect of a reg1 reg2 double mutant is alleviated by a loss-of-function mutation in the SNF1-encoded protein kinase. The snf1 mutation also suppresses the glucose repression defects of reg1. Together, our data are consistent with a model in which Reg1p and Reg2p control the activity of PP1 toward substrates that are phosphorylated by the Snf1p kinase.
authors.affiliation: Department of Genetics, North Carolina State University, Raleigh 27695, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Frederick
authors.forename: K
authors.initials: K
authors.lastname: Tatchell
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002455:Cell Division / Q000235:genetics / Q000502:physiology; D017931:DNA Primers / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D005800:Genes, Fungal; D005947:Glucose / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
chemical_list: D002352:Carrier Proteins; D017931:DNA Primers; D004271:DNA, Fungal; D005656:Fungal Proteins; C000623142:Reg2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D006003:Glycogen; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases; D010749:Phosphoprotein Phosphatases; D005947:Glucose