title: Stimulation by inositol trisphosphate and tetrakisphosphate of a protein phosphatase.
abstract: Several inositol trisphosphate isomers and inositol tetrakisphosphate activate a rat brain phosphoprotein phosphatase, using phosphohistone as well as phosphorylase kinase as substrate. Inositol mono- and bisphosphate have no effect. The protein phosphatase may correspond to type-1 since it is associated with the particulate fraction and is inhibited by heparin. Evidence is presented for the target of inositol phosphate being the catalytic subunit of the protein phosphatase. A parallelism is observed between the ability of the several inositol trisphosphates to activate the protein phosphatase and reported data indicating their ability to release calcium in permeabilized cells.
authors.affiliation: Cancer Research Center of Hawaii, University of Hawaii, Honolulu 96813.
authors.forename: J
authors.initials: J
authors.lastname: Zwiller
authors.forename: E M
authors.initials: EM
authors.lastname: Ogasawara
authors.forename: S S
authors.initials: SS
authors.lastname: Nakamoto
authors.forename: A L
authors.initials: AL
authors.lastname: Boynton
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D002793:Cholic Acids; D004305:Dose-Response Relationship, Drug; D006493:Heparin / Q000494:pharmacology; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000494:pharmacology*; D009132:Muscles / Q000201:enzymology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D051381:Rats; D013403:Sugar Phosphates / Q000494:pharmacology*
chemical_list: D002793:Cholic Acids; D007295:Inositol Phosphates; D013403:Sugar Phosphates; D015544:Inositol 1,4,5-Trisphosphate; D006493:Heparin; D010749:Phosphoprotein Phosphatases; C028213:3-((3-cholamidopropyl)dimethylammonium)-1-propanesulfonate