Pyruvate kinase type M2 is phosphorylated at tyrosine residues in cells transformed by Rous sarcoma virus

FEBS Lett. 1988 Dec 19;242(1):194-8. doi: 10.1016/0014-5793(88)81014-7.

Abstract

Chicken embryo cells (CECs) contain pyruvate kinase (PK) type M2 (M2-PK). Transformation of CECs by Rous sarcoma virus (RSV) leads to a reduction in the affinity of PK for the substrate phosphoenolpyruvate. In vitro, M2-PK can be phosphorylated at tyrosine residues by pp60v-src, the transforming protein of RSV. To study tyrosine phosphorylation of M2-PK in intact RSV-transformed cells, the protein was immunoprecipitated from 32P-labeled normal and RSV-SR-A-transformed CECs. Phosphoamino acid analysis of immunoprecipitated M2-PK revealed that M2-PK of both normal and transformed CECs contained phosphoserine and small amounts of phosphothreonine. Only M2-PK of transformed CECs contained phosphotyrosine in addition. For enzyme kinetic studies M2-PK was partially purified by chromatography upon DEAE-Sephacel and hydroxyapatite. A decreased affinity for phosphoenolpyruvate was observed 3 h after the onset of transformation using the temperature-sensitive mutant of RSV, ts-NY 68. The kinetic changes were correlated with tyrosine phosphorylation of M2-PK, but there is no direct evidence that they are caused by post-translational modification of the enzyme.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Avian Sarcoma Viruses*
  • Cell Transformation, Viral*
  • Chick Embryo
  • Immunosorbent Techniques
  • Kinetics
  • Oncogene Protein pp60(v-src)
  • Phosphoenolpyruvate / metabolism
  • Phosphorylation
  • Phosphoserine / metabolism
  • Phosphothreonine / metabolism
  • Phosphotyrosine
  • Protein-Tyrosine Kinases
  • Pyruvate Kinase / metabolism*
  • Retroviridae Proteins / metabolism
  • Tyrosine / analogs & derivatives*
  • Tyrosine / metabolism

Substances

  • Retroviridae Proteins
  • Phosphothreonine
  • Phosphoserine
  • Phosphotyrosine
  • Tyrosine
  • Phosphoenolpyruvate
  • Pyruvate Kinase
  • Protein-Tyrosine Kinases
  • Oncogene Protein pp60(v-src)