title: Rat liver contains a potent endogenous inhibitor of inositol 1,3,4,5-tetrakisphosphate 3-phosphatase.
abstract: When Ins(1,3,4,5)P4 was incubated with a rat liver 100,000 g supernatant, about 93% of the substrate was metabolized by a 5-phosphatase, and only 7% by a 3-phosphatase. Ion-exchange chromatography of the supernatant specifically increased its 3-phosphatase activity 72 +/- 3-fold. This activated enzyme was inhibited by a heat-stable factor present in both the soluble and particulate portions of the cell.
authors.affiliation: Inositol Lipid Section, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709.
authors.forename: M E
authors.initials: ME
authors.lastname: Hodgson
authors.forename: S B
authors.initials: SB
authors.lastname: Shears
mesh_terms: D000818:Animals; D002852:Chromatography, Ion Exchange; D004789:Enzyme Activation; D007295:Inositol Phosphates / Q000378:metabolism*; D000072181:Inositol Polyphosphate 5-Phosphatases; D008099:Liver / Q000032:analysis / Q000201:enzymology*; D010744:Phosphoric Monoester Hydrolases / Q000032:analysis / Q000037:antagonists & inhibitors*; D051381:Rats
chemical_list: D007295:Inositol Phosphates; C081655:inositol-1,3,4,5-tetrakisphosphate; D010744:Phosphoric Monoester Hydrolases; D000072181:Inositol Polyphosphate 5-Phosphatases; C064119:multiple inositol-polyphosphate phosphatase