Identification of reelin-induced sites of tyrosyl phosphorylation on disabled 1

J Biol Chem. 2001 May 11;276(19):16008-14. doi: 10.1074/jbc.M101422200. Epub 2001 Feb 23.

Abstract

The study of mice with spontaneous and targeted mutations has uncovered a signaling pathway that controls neuronal positioning during mammalian brain development. Mice with disruptions in reelin, dab1, or both vldlr and apoER2 are ataxic, and they exhibit severe lamination defects within several brain structures. Reelin is a secreted extracellular protein that binds to the very low density lipoprotein receptor and the apolipoprotein E receptor 2 on the surface of neurons. Disabled-1 (Dab1), an intracellular adapter protein containing a PTB (phosphotyrosine binding) domain, is tyrosyl-phosphorylated during embryogenesis, but it accumulates in a hypophosphorylated form in mice lacking Reelin or both very low density lipoprotein receptor and apolipoprotein E receptor 2. Dab1 is rapidly phosphorylated when neurons isolated from embryonic brains are stimulated with Reelin, and several tyrosines have been implicated in this response. Mice with phenylalanine substitutions of all five tyrosines (Tyr(185), Tyr(198), Tyr(200), Tyr(220), and Tyr(232)) exhibit a reeler phenotype, implying that tyrosine phosphorylation is critical for Dab1 function. Here we report that, although Src can phosphorylate all five tyrosines in vitro, Tyr(198) and Tyr(220) represent the major sites of Reelin-induced Dab1 phosphorylation in embryonic neurons.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Brain / growth & development
  • Brain / physiology*
  • Cell Adhesion Molecules, Neuronal / deficiency
  • Cell Adhesion Molecules, Neuronal / genetics
  • Cell Adhesion Molecules, Neuronal / metabolism*
  • Extracellular Matrix Proteins / deficiency
  • Extracellular Matrix Proteins / genetics
  • Extracellular Matrix Proteins / metabolism*
  • Mice
  • Mice, Knockout
  • Molecular Sequence Data
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neurons / physiology*
  • Peptide Fragments / chemistry
  • Phosphopeptides / chemistry
  • Phosphoproteins / genetics
  • Phosphorylation
  • Phosphotyrosine / metabolism*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Serine Endopeptidases
  • Signal Transduction

Substances

  • Cell Adhesion Molecules, Neuronal
  • Dab1 protein, mouse
  • Extracellular Matrix Proteins
  • Nerve Tissue Proteins
  • Peptide Fragments
  • Phosphopeptides
  • Phosphoproteins
  • Recombinant Fusion Proteins
  • Phosphotyrosine
  • Serine Endopeptidases
  • reelin protein