An ITIM-like motif within the CCK2 receptor sequence required for interaction with SHP-2 and the activation of the AKT pathway

Biochim Biophys Acta. 2006 Oct;1763(10):1098-107. doi: 10.1016/j.bbamcr.2006.07.003. Epub 2006 Jul 21.

Abstract

SHP-2 is a tyrosine phosphatase which functions as a positive regulator downstream of RTKs, activating growth-stimulatory signalling pathways. To date, very few G protein-coupled receptors (GPCRs) have been shown to be connected to SHP-2 and very little is known about the positive role of SHP-2 in GPCR signalling. The CCK2 receptor (CCK2R), a GPCR, is now recognized to mediate mitogenic effects of gastrin on gastrointestinal cells. In the present study, we demonstrate the role of SHP-2 in the activation of the AKT pathway by the CCK2R in COS-7 cells transfected with the CCK2R and in a pancreatic cancer cell line expressing the endogenous receptor. Using surface plasmon resonance analysis, we identified a highly conserved ITIM motif, containing the tyrosine residue 438, located in the C-terminal intracellular tail of the CCK2R which directly interacts with the SHP-2 SH2 domains. The interaction was confirmed by pull down assays and co-immunoprecipitation of the receptor with SHP-2. This interaction was transiently increased following gastrin stimulation of the CCK2R and correlated with the tyrosine phosphorylation of SHP-2. Mutational analysis of the key ITIM residue 438 confirmed that the CCK2R ITIM sequence is required for interaction with SHP-2 and the activation of the AKT pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • COS Cells
  • Cell Line, Tumor
  • Chlorocebus aethiops
  • Gastrins / pharmacology
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Intracellular Signaling Peptides and Proteins / physiology
  • Mice
  • Molecular Sequence Data
  • NIH 3T3 Cells
  • Pancreatic Neoplasms / metabolism*
  • Phosphorylation
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Protein Tyrosine Phosphatases / metabolism*
  • Protein Tyrosine Phosphatases / physiology
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Rats
  • Receptor, Cholecystokinin B / genetics
  • Receptor, Cholecystokinin B / metabolism*
  • Receptor, Cholecystokinin B / physiology
  • Signal Transduction
  • Tyrosine / metabolism

Substances

  • Gastrins
  • Intracellular Signaling Peptides and Proteins
  • Receptor, Cholecystokinin B
  • Tyrosine
  • Proto-Oncogene Proteins c-akt
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Protein Tyrosine Phosphatases
  • Ptpn11 protein, mouse
  • Ptpn11 protein, rat