title: Characterisation of a novel Drosophila melanogaster testis specific PP1 inhibitor related to mammalian inhibitor-2: identification of the site of interaction with PP1.
abstract: A novel Drosophila melanogaster protein, termed inhibitor-t, that bears 41% sequence similarity to human protein phosphatase inhibitor-2 has been identified using human protein phosphatase 1 (PP1) in the yeast two hybrid system. Inhibitor-t mRNA is detected in adult males, larvae and pupae and the 184 amino acid thermostable protein located only in testis. The gene for inhibitor-t maps to cytological location 86F1 on the third chromosome. Bacterially expressed inhibitor-t specifically inhibits both mammalian and D. melanogaster PP1 catalytic subunits with an IC50 of approximately 200 nM. A motif -FEX1X2RK-, conserved between inhibitor-t, inhibitor-2 and its Saccharomyces cerevisiae homologue Glc8, is demonstrated to be required for binding to PP1.
authors.affiliation: Department of Biochemistry, University of Dundee, UK. nrhelps@bad.dundee.ac.uk
authors.forename: N R
authors.initials: NR
authors.lastname: Helps
authors.forename: C
authors.initials: C
authors.lastname: Vergidou
authors.forename: T
authors.initials: T
authors.lastname: Gaskell
authors.forename: P T
authors.initials: PT
authors.lastname: Cohen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D020134:Catalytic Domain; D002874:Chromosome Mapping; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000737:chemistry / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000235:genetics; D017344:Genes, Insect; D006801:Humans; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D007814:Larva / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000302:isolation & purification / Q000378:metabolism; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011679:Pupa / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013737:Testis / Q000737:chemistry; D000097847:Protein Phosphatase Inhibitory Proteins
chemical_list: D029721:Drosophila Proteins; D004791:Enzyme Inhibitors; D019476:Insect Proteins; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D017346:Protein Serine-Threonine Kinases; D011506:Proteins; D011994:Recombinant Proteins; C115665:I-T protein, Drosophila; C024833:protein phosphatase inhibitor-2; D000097847:Protein Phosphatase Inhibitory Proteins; C517102:PPP1CC protein, human