title: Tyrosine phosphorylation of netrin receptors in netrin-1 signaling.
abstract: Deleted in colorectal cancer (DCC) and neogenin are receptors of netrins, a family of guidance cues that promote axon outgrowth and guide growth cones in developing nervous system. The intracellular mechanisms of netrins, however, remain elusive. In this paper, we show that both DCC and neogenin become tyrosine phosphorylated in cortical neurons in response to netrin-1. Using a site-specific antiphosphor DCC antibody, we show that Y1420 phosphorylation is increased in netrin-1-stimulated neurons and that tyrosine-phosphorylated DCC is located in growth cones. In addition, we show that tyrosine-phosphorylated DCC selectively interacts with the Src family kinases Fyn and Lck, but not Src, c-Abl, Grb2, SHIP1, Shc, or tensin, suggesting a role of Fyn or Lck in netrin-1-DCC signaling. Of interest to note is that tyrosine-phosphorylated neogenin and uncoordinated 5 H2 (Unc5H2) not only bind to the Src homology 2 (SH2) domains of Fyn and SHP2, but also interact with the SH2 domain of SHIP1, suggesting a differential signaling between DCC and neogenin/Unc5H2. Furthermore, we demonstrate that inhibition of Src family kinase activity attenuated netrin-1-induced neurite outgrowth. Together, these results suggest a role of Src family kinases and tyrosine phosphorylation of netrin-1 receptors in regulating netrin-1 function.
authors.affiliation: Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Xiu-Rong
authors.initials: XR
authors.lastname: Ren
authors.forename: Yan
authors.initials: Y
authors.lastname: Hong
authors.forename: Zhu
authors.initials: Z
authors.lastname: Feng
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Yang
authors.forename: Lin
authors.initials: L
authors.lastname: Mei
authors.forename: Wen-Cheng
authors.initials: WC
authors.lastname: Xiong
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D002645:Chickens; D000075389:DCC Receptor; D005260:Female; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D000075386:Netrin Receptors; D000075388:Netrin-1; D009474:Neurons / Q000166:cytology / Q000502:physiology; D010766:Phosphorylation; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D014443:Tyrosine / Q000235:genetics / Q000378:metabolism*
chemical_list: D000075389:DCC Receptor; C501909:DCC protein, human; D008565:Membrane Proteins; C000617351:NTN1 protein, human; D009414:Nerve Growth Factors; D000075386:Netrin Receptors; C000617354:Ntn1 protein, rat; D011956:Receptors, Cell Surface; D025521:Tumor Suppressor Proteins; C091279:neogenin; D000075388:Netrin-1; D014443:Tyrosine