Akt binds to and phosphorylates phospholipase C-gamma1 in response to epidermal growth factor

Mol Biol Cell. 2006 May;17(5):2267-77. doi: 10.1091/mbc.e05-10-0918. Epub 2006 Mar 8.

Abstract

Both phospholipase (PL) C-gamma1 and Akt (protein kinase B; PKB) are signaling proteins that play significant roles in the intracellular signaling mechanism used by receptor tyrosine kinases, including epidermal growth factor (EGF) receptor (EGFR). EGFR activates PLC-gamma1 directly and activates Akt indirectly through phosphatidylinositol 3-kinase (PI3K). Many studies have shown that the PLC-gamma1 pathway and PI3K-Akt pathway interact with each other. However, it is not known whether PLC-gamma1 binds to Akt directly. In this communication, we identified a novel interaction between PLC-gamma1 and Akt. We demonstrated that the interaction is mediated by the binding of PLC-gamma1 Src homology (SH) 3 domain to Akt proline-rich motifs. We also provide a novel model to depict how the interaction between PLC-gamma1 SH3 domain and Akt proline-rich motifs is dependent on EGF stimulation. In this model, phosphorylation of PLC-gamma1 Y783 by EGF causes the conformational change of PLC-gamma1 to allow the interaction of its SH3 domain with Akt proline-rich motifs. Furthermore, we showed that the interaction between PLC-gamma1 and Akt resulted in the phosphorylation of PLC-gamma1 S1248 by Akt. Finally, we showed that the interaction between PLC-gamma1 and Akt enhanced EGF-stimulated cell motility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • COS Cells
  • Cell Movement*
  • Chlorocebus aethiops
  • Epidermal Growth Factor / pharmacology*
  • Phospholipase C gamma / analysis
  • Phospholipase C gamma / genetics
  • Phospholipase C gamma / metabolism*
  • Phosphorylation
  • Proline / genetics
  • Proline / metabolism
  • Protein Conformation
  • Protein Interaction Mapping
  • Proto-Oncogene Proteins c-akt / analysis
  • Proto-Oncogene Proteins c-akt / metabolism*
  • src Homology Domains / genetics

Substances

  • Epidermal Growth Factor
  • Proline
  • Proto-Oncogene Proteins c-akt
  • Phospholipase C gamma