title: Tyrosine phosphorylation of the CrkII adaptor protein modulates cell migration.
abstract: CrkII belongs to a family of adaptor proteins that become tyrosine phosphorylated after various stimuli. We examined the role of CrkII tyrosine phosphorylation in fibronectin-induced cell migration. Overexpression of CrkII inhibited dephosphorylation of focal adhesion components such as p130 Crk-associated substrate (p130cas) and paxillin by protein tyrosine phosphatase 1B (PTP1B). Tyrosine-phosphorylated CrkII was dephosphorylated by PTP1B both in vitro and in vivo, showing for the first time that PTP1B directly dephosphorylates CrkII. A CrkII mutant in which tyrosine residue 221 was substituted by phenylalanine (CrkII-Y221F) could not be tyrosine phosphorylated, and it showed significantly increased binding to p130cas and paxillin. Enhanced binding of CrkII to p130cas has been reported to promote cell migration. Nonphosphorylated CrkII-Y221F promoted HT1080 cell migration on fibronectin, whereas wild-type CrkII did not at moderate expression levels. Moreover, co-expression of CrkII and PTP1B promoted HT1080 cell migration on fibronectin and retained tyrosine phosphorylation and binding of p130cas to CrkII, whereas paxillin tyrosine phosphorylation was reduced. These findings support the concepts that CrkII binding activity is regulated by tyrosine kinases and phosphatases, and that tyrosine phosphorylation of CrkII can downmodulate cell migration mediated by the focal adhesion kinase/p130cas pathway.
authors.affiliation: Craniofacial Developmental Biology and Regeneration Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4370, USA.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Takino
authors.forename: Masahito
authors.initials: M
authors.lastname: Tamura
authors.forename: Hisashi
authors.initials: H
authors.lastname: Miyamori
authors.forename: Masaru
authors.initials: M
authors.lastname: Araki
authors.forename: Kazue
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Yamada
mesh_terms: D002465:Cell Movement; D002478:Cells, Cultured; D050719:Crk-Associated Substrate Protein; D003598:Cytoskeletal Proteins / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins; D008856:Microscopy, Fluorescence; D009154:Mutation; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011506:Proteins; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D050737:Proto-Oncogene Proteins c-crk; D034741:RNA, Small Interfering / Q000494:pharmacology; D011994:Recombinant Proteins / Q000378:metabolism; D050717:Retinoblastoma-Like Protein p130; D014443:Tyrosine / Q000378:metabolism
chemical_list: C493841:BCAR1 protein, human; D050719:Crk-Associated Substrate Protein; D003598:Cytoskeletal Proteins; D005353:Fibronectins; D008164:Luminescent Proteins; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D050737:Proto-Oncogene Proteins c-crk; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D050717:Retinoblastoma-Like Protein p130; D049452:Green Fluorescent Proteins; D014443:Tyrosine; C516607:PTPN1 protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases