title: RPTPalpha and PTPepsilon signaling via Fyn/Yes and RhoA is essential for zebrafish convergence and extension cell movements during gastrulation.
abstract: Convergence and extension (C&E) cell movements are essential to shape the body axis during vertebrate gastrulation. We have used the zebrafish to assess the role of the receptor protein-tyrosine phosphatases, RPTPalpha and PTPepsilon, in gastrulation cell movements. Both RPTPalpha and PTPepsilon knockdown and ptpra(-/-) embryos show defects in C&E movements. A method was developed to track gastrulation cell movements using confocal microscopy in a quantitative manner and ptpra(-/-) embryos displayed reduced convergence as well as extension speeds. RPTPalpha and PTPepsilon knockdowns cooperated with knockdown of a well known factor in C&E cell movement, non-canonical Wnt11. RPTPalpha and PTPepsilon dephosphorylate and activate Src family kinases in various cell types in vitro and in vivo. We found that Src family kinase phosphorylation was enhanced in ptpra(-/-) embryos, consistent with reduced Src family kinase activity. Importantly, both ptpra(-/-) and RPTPalpha and PTPepsilon knockdown induced C&E defects were rescued by active Fyn and Yes. Moreover, active RhoA rescued the RPTPalpha and PTPepsilon knockdown and ptpra(-/-) induced gastrulation cell movement defects as well. Our results demonstrate that RPTPalpha and PTPepsilon are essential for C&E movements in a signaling pathway parallel to non-canonical Wnts and upstream of Fyn, Yes and RhoA.
authors.affiliation: Hubrecht Institute - KNAW and University Medical Center Utrecht, The Netherlands.
authors.forename: Mark
authors.initials: M
authors.lastname: van Eekelen
authors.forename: Vincent
authors.initials: V
authors.lastname: Runtuwene
authors.forename: John
authors.initials: J
authors.lastname: Overvoorde
authors.forename: Jeroen
authors.initials: J
authors.lastname: den Hertog
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000502:physiology; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000502:physiology; D054262:Gastrulation / Q000502:physiology*; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000502:physiology*; D051076:Proto-Oncogene Proteins c-fyn / Q000235:genetics / Q000502:physiology*; D054630:Receptor-Like Protein Tyrosine Phosphatases, Class 4 / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029961:Zebrafish Proteins / Q000235:genetics / Q000502:physiology*; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000502:physiology*
chemical_list: D029961:Zebrafish Proteins; D051076:Proto-Oncogene Proteins c-fyn; C494964:fyna protein, zebrafish; C549426:Ptpre protein, zebrafish; D054630:Receptor-Like Protein Tyrosine Phosphatases, Class 4; C516847:ptpra protein, zebrafish; D020559:Monomeric GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein; C549425:rhoab protein, zebrafish