Shp-2 specifically regulates several tyrosine-phosphorylated proteins in brain-derived neurotrophic factor signaling in cultured cerebral cortical neurons

J Neurochem. 2000 Feb;74(2):659-68. doi: 10.1046/j.1471-4159.2000.740659.x.

Abstract

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophins, promotes differentiation and survival and regulates plasticity of various types of neurons. BDNF binds to TrkB, a receptor tyrosine kinase, which results in the activation of a variety of signaling molecules to exert the various functions of BDNF. Shp-2, a Src homology 2 domain-containing cytoplasmic tyrosine phosphatase, is involved in neurotrophin signaling in PC12 cells and cultured cerebral cortical neurons. To examine the roles of Shp-2 in BDNF signaling in cultured rat cerebral cortical neurons, the wild-type and phosphatase-inactive mutant (C/S mutant) forms of Shp-2 were ectopically expressed in cultured neurons using recombinant adenovirus vectors. We found that several proteins tyrosine-phosphorylated in response to BDNF showed enhanced levels of tyrosine phosphorylation in cultured neurons infected with C/S mutant adenovirus in comparison with those infected with the wild-type Shp-2 adenovirus. In addition, in immunoprecipitates with anti-Shp-2 antibody, we also observed at least four proteins that displayed enhanced phosphorylation in response to BDNF in cultured neurons infected with the C/S mutant adenovirus. We found that the Shp-2-binding protein, brain immunoglobulin-like molecule with tyrosine-based activation motifs (BIT), was strongly tyrosine-phosphorylated in response to BDNF in cultured neurons expressing the C/S mutant of Shp-2. In contrast, the level of BDNF-induced phosphorylation of mitogen-activated protein kinase and coprecipitated proteins with anti-Trk and Grb2 antibodies did not show any difference between neurons infected with these two types of Shp-2. Furthermore, the survival effect of BDNF was enhanced by the wild type of Shp-2, although it was not influenced by the C/S mutant of Shp-2. These results indicated that in cultured cerebral cortical neurons Shp-2 is specifically involved in the regulation of several tyrosine-phosphorylated proteins, including BIT, in the BDNF signaling pathway. In addition, the phosphatase Shp-2 may not influence the level of BDNF-induced activation of mitogen-activated protein kinase in cultured cortical neurons. Further, Shp-2 may have potential to positively regulate BDNF-promoting neuronal survival.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing*
  • Animals
  • Antigens, Differentiation*
  • Brain-Derived Neurotrophic Factor / physiology*
  • Cells, Cultured
  • Cerebral Cortex / cytology
  • Cerebral Cortex / metabolism*
  • Enzyme Activation / physiology
  • Female
  • GRB2 Adaptor Protein
  • Intracellular Signaling Peptides and Proteins
  • Male
  • Membrane Glycoproteins / metabolism
  • Mitogen-Activated Protein Kinases / metabolism
  • Mutation / genetics
  • Mutation / physiology
  • Neural Cell Adhesion Molecule L1*
  • Neural Cell Adhesion Molecules / metabolism
  • Neurons / metabolism
  • Phosphoproteins / metabolism*
  • Phosphoric Monoester Hydrolases / metabolism
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6
  • Protein Tyrosine Phosphatases / genetics
  • Protein Tyrosine Phosphatases / physiology*
  • Proteins / metabolism
  • Rats
  • Rats, Wistar
  • Receptor, trkA / metabolism
  • Receptor, trkB / metabolism
  • Receptors, Immunologic*
  • Signal Transduction / physiology*
  • Tyrosine / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • Antigens, Differentiation
  • Brain-Derived Neurotrophic Factor
  • GRB2 Adaptor Protein
  • Grb2 protein, rat
  • Intracellular Signaling Peptides and Proteins
  • Membrane Glycoproteins
  • Neural Cell Adhesion Molecule L1
  • Neural Cell Adhesion Molecules
  • Phosphoproteins
  • Proteins
  • Receptors, Immunologic
  • Tyrosine
  • Receptor, trkA
  • Receptor, trkB
  • Mitogen-Activated Protein Kinases
  • Phosphoric Monoester Hydrolases
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Protein Tyrosine Phosphatase, Non-Receptor Type 6
  • Protein Tyrosine Phosphatases
  • Ptpn11 protein, rat
  • Ptpn6 protein, rat