Phosphorylation of p36 in vitro with pp60src. Regulation by Ca2+ and phospholipid

FEBS Lett. 1985 Nov 11;192(1):79-82. doi: 10.1016/0014-5793(85)80047-8.

Abstract

P36 is a major substrate of the tyrosine protein kinases. P36 isolated from bovine intestine was used in phosphorylation reactions with pp60src. Phosphorylation was stimulated 3-5-fold by Ca2+, however the Km was the same (2.5 microM) at high or low Ca2+. Although the level of free Ca2+ needed for this enhanced phosphorylation was 10(-4)-10(-3) M, phosphatidylserine shifted the Ca2+ sensitivity to the 10(-6)-10(-5) M range. Independent evidence suggested that p36 interacts directly with liposomes containing phosphatidylserine. This raises the possibility that p36, like c-kinase, is a Ca2+-activated, phospholipid-dependent protein.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Annexins
  • Calcium / pharmacology*
  • Cattle
  • Intestines / analysis
  • Kinetics
  • Membrane Proteins / metabolism*
  • Oncogene Protein pp60(v-src)
  • Phosphatidylinositols / pharmacology
  • Phosphatidylserines / pharmacology
  • Phospholipids / pharmacology*
  • Phosphorylation
  • Phosphotyrosine
  • Protein-Tyrosine Kinases / metabolism
  • Retroviridae Proteins / metabolism*
  • Tyrosine / analogs & derivatives
  • Tyrosine / metabolism

Substances

  • Annexins
  • Membrane Proteins
  • Phosphatidylinositols
  • Phosphatidylserines
  • Phospholipids
  • Retroviridae Proteins
  • Phosphotyrosine
  • Tyrosine
  • Protein-Tyrosine Kinases
  • Oncogene Protein pp60(v-src)
  • Calcium