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.

SUBMITTER: Hodgson ME 

PROVIDER: S-EPMC1131373 | biostudies-other | 1990 May

REPOSITORIES: biostudies-other