title: A PTP-PEST-like protein affects alpha5beta1-integrin-dependent matrix assembly, cell adhesion, and migration in Xenopus gastrula.
abstract: During amphibian gastrulation, mesodermal cell movements depend on both cell-cell and cell-matrix interactions. Ectodermal cells from the blastocoel roof use alpha5beta1 integrins to assemble a fibronectin-rich extracellular matrix on which mesodermal cells migrate using the same alpha5beta1 integrin. In this report, we show that the tyrosine phosphatase xPTP-PESTr can prevent fibronectin fibril formation when overexpressed in ectodermal cells resulting in delayed gastrulation. In addition, isolated ectodermal cells overexpressing xPTP-PESTr are able to spread on fibronectin using the alpha5beta1 integrin in the absence of activin-A induction and before the onset of gastrulation. We further show that while the inhibition of fibrillogenesis depends on the phosphatase activity of xPTP-PESTr, induction of cell spreading does not. Finally, while cell spreading is usually associated with cell migration, xPTP-PESTr promotes ectodermal cell spreading on fibronectin but also reduces cell migration in response to activin-A, suggesting an adverse effect on cell translocation. We propose that xPTP-PESTr overexpression adversely affect cell migration by preventing de-adhesion of cells from the substrate.
authors.affiliation: Paige Laboratory, Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Hélène
authors.initials: H
authors.lastname: Cousin
authors.forename: Dominique
authors.initials: D
authors.lastname: Alfandari
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D005353:Fibronectins / Q000096:biosynthesis; D005775:Gastrula / Q000201:enzymology*; D039081:Integrin alpha5beta1 / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D054594:Protein Tyrosine Phosphatase, Non-Receptor Type 12; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism*; D011506:Proteins; D050717:Retinoblastoma-Like Protein p130; D029867:Xenopus Proteins; D014982:Xenopus laevis
chemical_list: D003598:Cytoskeletal Proteins; D005353:Fibronectins; D039081:Integrin alpha5beta1; C496060:PXN protein, Xenopus; D051419:Paxillin; D010750:Phosphoproteins; D011506:Proteins; D050717:Retinoblastoma-Like Protein p130; D029867:Xenopus Proteins; D054594:Protein Tyrosine Phosphatase, Non-Receptor Type 12; D017027:Protein Tyrosine Phosphatases