The SH2/SH3 domain-containing protein Nck is recognized by certain anti-phospholipase C-gamma 1 monoclonal antibodies, and its phosphorylation on tyrosine is stimulated by platelet-derived growth factor and epidermal growth factor treatment

Mol Cell Biol. 1992 Dec;12(12):5843-56. doi: 10.1128/mcb.12.12.5843.

Abstract

In the course of our investigation of phospholipase C (PLC)-gamma 1 phosphorylation by using a set of anti-PLC-gamma 1 monoclonal antibodies (P.-G. Suh, S. H. Ryu, W. C. Choi, K.-Y. Lee, and S. G. Rhee, J. Biol. Chem. 263:14497-14504, 1988), we found that some of these antibodies directly recognize a 47-kDa protein. We show here that this 47-kDa protein is identical to the SH2/SH3-containing protein Nck (J. M. Lehmann, G. Riethmuller, and J. P. Johnson, Nucleic Acids Res. 18:1048, 1990). Nck was found to be constitutively phosphorylated on serine in resting NIH 3T3 cells. Platelet-derived growth factor (PDGF) treatment led to increased Nck phosphorylation on both tyrosine and serine. Nck was also found to be phosphorylated on tyrosine in epidermal growth factor (EGF)-treated A431 cells and in v-Src-transformed NIH 3T3 cells. Multiple sites of serine phosphorylation were detected in Nck from resting cells, and no novel sites were found upon PDGF or EGF treatment. A single major tyrosine phosphorylation site was found in Nck in both PDGF- and EGF-treated cells and in v-Src-transformed cells. This same tyrosine was phosphorylated in vitro by purified PDGF and EGF receptors and also by pp60c-src. We compared the phosphorylation of Nck and PLC-gamma 1 in several cell lines transformed by oncogenes with different modes of transformation. Although PLC-gamma 1 and Nck have significant amino acid identity, particularly in their SH3 regions, and both associate with growth factor receptors in a ligand-dependent manner, they were not always phosphorylated on tyrosine in a coincident manner.

Publication types

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

MeSH terms

  • 3T3 Cells
  • Adaptor Proteins, Signal Transducing
  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / immunology
  • Cattle
  • Cell Division
  • Cell Line
  • Epidermal Growth Factor / pharmacology*
  • Humans
  • Mice
  • Molecular Sequence Data
  • Oncogene Proteins / chemistry
  • Oncogene Proteins / immunology
  • Oncogene Proteins / metabolism*
  • Peptide Mapping
  • Phosphorylation
  • Platelet-Derived Growth Factor / pharmacology*
  • Precipitin Tests
  • Rats
  • Sequence Homology, Amino Acid
  • Serine / metabolism
  • Sulfhydryl Compounds / metabolism*
  • Type C Phospholipases / immunology*
  • Type C Phospholipases / metabolism
  • Tyrosine / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Antibodies, Monoclonal
  • Nck protein
  • Oncogene Proteins
  • Platelet-Derived Growth Factor
  • Sulfhydryl Compounds
  • Tyrosine
  • Serine
  • Epidermal Growth Factor
  • Type C Phospholipases