title: Inhibitor-1 and -2 of PP2A have preference between PP2A complexes.
abstract: Protein phosphatase 2A (PP2A) forms tens of kinds of complexes with different substrate specificity and functions by using various regulatory B subunits. But how these complexes' activities are regulated separately is not well understood. Here we showed unequal enzyme inhibition of each form by two proteinous PP2A inhibitors, I1(PP2A) and I2(PP2A). Immunoprecipitation assay using Xenopus egg extract showed that I1(PP2A) bound B″/PR48, and I2(PP2A) bound B56γ and B″/PR48 among four B subunits analyzed. Thus I1(PP2A) and I2(PP2A) seem to have B-subunit specificity. These results support the hypothesis that PP2A complexes containing common catalytic subunit are individually regulated for their separate functions in vivo.
authors.affiliation: Priority Organization for Innovation and Excellence, Kumamoto University, Honjo-Kyoyotou, 2-2-1 Honjo, Chuo-ku, Kumamoto City, Kumamoto 860-0811, Japan.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Hino
authors.affiliation: Priority Organization for Innovation and Excellence, Kumamoto University, Honjo-Kyoyotou, 2-2-1 Honjo, Chuo-ku, Kumamoto City, Kumamoto 860-0811, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Takaki
authors.affiliation: Priority Organization for Innovation and Excellence, Kumamoto University, Honjo-Kyoyotou, 2-2-1 Honjo, Chuo-ku, Kumamoto City, Kumamoto 860-0811, Japan; Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Honjo-Kyoyotou, 2-2-1 Honjo, Chuo-ku, Kumamoto City, Kumamoto 860-0811, Japan; International Research Center for Medical Sciences (IRCMS), Kumamoto University, Honjo-Kyoyotou, 2-2-1 Honjo, Chuo-ku, Kumamoto City, Kumamoto 860-0811, Japan; PRESTO Program, Japan Science and Technology Agency, Japan. Electronic address: mochida@kumamoto-u.ac.jp.
authors.forename: Satoru
authors.initials: S
authors.lastname: Mochida
mesh_terms: D000818:Animals; D001665:Binding Sites; D020134:Catalytic Domain; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D007399:Interphase / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D007700:Kinetics; D010063:Ovum / Q000737:chemistry / Q000166:cytology / Q000201:enzymology*; D010312:Parthenogenesis / Q000235:genetics; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D054648:Protein Phosphatase 2 / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D029867:Xenopus Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis
chemical_list: D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; D029867:Xenopus Proteins; D054648:Protein Phosphatase 2; C584831:ppp2r2a protein, Xenopus laevis
keywords: B-subunit specificity; I1(PP2A); I2(PP2A); Inhibitor protein; PP2A