Turkey erythrocytes possess a membrane-associated inositol 1,4,5-trisphosphate 3-kinase that is activated by Ca2+ in the presence of calmodulin

Biochem J. 1987 Dec 1;248(2):489-93. doi: 10.1042/bj2480489.

Abstract

Turkey erythrocytes contain soluble and particulate kinase activities which catalyse the ATP-dependent phosphorylation of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3]. The particle-bound activity accounts for approximately one-quarter of the total cellular Ins(1,4,5)P3 kinase, when assayed at a [Ca2+] of 10 nM. The particle-bound Ins(1,4,5)P3 kinase is not washed from the membrane by 0.6 M-KCl, yet may be solubilized by a variety of detergents. This suggests that it is an intrinsic membrane protein. The product of the membrane-bound Ins(1,4,5)P3 kinase is inositol 1,3,4,5-tetrakisphosphate [Ins(1,3,4,5)P4], identifying the enzyme as an Ins(1,4,5)P3 3-kinase. In the presence of calmodulin, the membrane-associated Ins(1,4,5)P3 3-kinase is activated as [Ca2+] is increased over the range 0.2-1.0 microM. Under these conditions, the rates of dephosphorylation of Ins(1,3,4,5)P4 and Ins(1,4,5)P3 by phosphatases in the membrane fraction are unchanged.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / pharmacology*
  • Calmodulin / pharmacology*
  • Enzyme Activation / drug effects
  • Erythrocyte Membrane / drug effects
  • Erythrocyte Membrane / enzymology*
  • In Vitro Techniques
  • Phosphotransferases (Alcohol Group Acceptor)*
  • Phosphotransferases / blood*
  • Turkeys

Substances

  • Calmodulin
  • Phosphotransferases
  • Phosphotransferases (Alcohol Group Acceptor)
  • Inositol 1,4,5-trisphosphate 3-kinase
  • Calcium