title: Phosphorylation of DCC by Fyn mediates Netrin-1 signaling in growth cone guidance.
abstract: Netrin-1 acts as a chemoattractant molecule to guide commissural neurons (CN) toward the floor plate by interacting with the receptor deleted in colorectal cancer (DCC). The molecular mechanisms underlying Netrin-1-DCC signaling are still poorly characterized. Here, we show that DCC is phosphorylated in vivo on tyrosine residues in response to Netrin-1 stimulation of CN and that the Src family kinase inhibitors PP2 and SU6656 block both Netrin-1-dependent phosphorylation of DCC and axon outgrowth. PP2 also blocks the reorientation of Xenopus laevis retinal ganglion cells that occurs in response to Netrin-1, which suggests an essential role of the Src kinases in Netrin-1-dependent orientation. Fyn, but not Src, is able to phosphorylate the intracellular domain of DCC in vitro, and we demonstrate that Y1418 is crucial for DCC axon outgrowth function. Both DCC phosphorylation and Netrin-1-induced axon outgrowth are impaired in Fyn(-/-) CN and spinal cord explants. We propose that DCC is regulated by tyrosine phosphorylation and that Fyn is essential for the response of axons to Netrin-1.
authors.affiliation: Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, H3A 2B2, Canada.
authors.forename: Mayya
authors.initials: M
authors.lastname: Meriane
authors.forename: Joseph
authors.initials: J
authors.lastname: Tcherkezian
authors.forename: Christine A
authors.initials: CA
authors.lastname: Webber
authors.forename: Eric I
authors.initials: EI
authors.lastname: Danek
authors.forename: Ibtissem
authors.initials: I
authors.lastname: Triki
authors.forename: Sarah
authors.initials: S
authors.lastname: McFarlane
authors.forename: Evelyne
authors.initials: E
authors.lastname: Bloch-Gallego
authors.forename: Nathalie
authors.initials: N
authors.lastname: Lamarche-Vane
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D000075389:DCC Receptor; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D020439:Growth Cones / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009414:Nerve Growth Factors / Q000378:metabolism* / Q000494:pharmacology; D000075388:Netrin-1; D010766:Phosphorylation / Q000187:drug effects; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051076:Proto-Oncogene Proteins c-fyn; D051381:Rats; D011956:Receptors, Cell Surface; D012160:Retina / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism; D029867:Xenopus Proteins; D014982:Xenopus laevis; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D015815:Cell Adhesion Molecules; D000075389:DCC Receptor; C501910:Dcc protein, mouse; D004791:Enzyme Inhibitors; D009414:Nerve Growth Factors; C000617353:Ntn1 protein, mouse; C000617354:Ntn1 protein, rat; D011518:Proto-Oncogene Proteins; D011956:Receptors, Cell Surface; D025521:Tumor Suppressor Proteins; D029867:Xenopus Proteins; D000075388:Netrin-1; D014443:Tyrosine; C494963:Fyn protein, Xenopus; C494960:Fyn protein, mouse; C494961:Fyn protein, rat; D051076:Proto-Oncogene Proteins c-fyn; D019061:src-Family Kinases