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.

Temporal Dissection of β1-Integrin Signaling Indicates a Role for p130Cas-Crk in Filopodia Formation

“…Fibroblasts deficient in p130Cas exhibit decreased actin filament formation with disorganized F-actin architecture, and these cells are also affected in migration (55). In analogy, overexpression of p130Cas or Crk is sufficient to induce cell migration, which depends on the coupling of tyrosine-phosphorylated p130Cas with dephosphorylated Crk (40,49,51). The p130Cas protein localizes both to the cytoplasm or perinuclear region and to adhesion sites of adherent cells.…”

“…3D). Dephosphorylation of CrkII has previously been observed to increase the CrkII-p130Cas association and subsequent cell migration (51). To investigate the importance of Crk in ␤ 1B -integrin-mediated filopodia formation, GD25␤ 1B cells were transfected with GFPtagged full-length CrkII, GFP-tagged CrkII Src homology 2 (SH2) domain, or GFP-tagged CrkII SH3 domain 1.…”

Protein tyrosine phosphatase PTP1B in cell adhesion and migration

“…PTP1B was shown to promote cell adhesion and motility in fibroblasts, 17,18 neurons, 3,19 platelets, 4 and several tumor cell lines. 12,[20][21][22] An inhibitory role has been described in fibroblasts, 23,24 primary aortic smooth muscle cells, 25 ovarian cancer cells, 26 and in glioblastoma multiforme tumor cell invasion in mice. 27 Remarkably, the positive role of PTP1B in cell motility was frequently associated with the stimulation of integrin-dependent signaling.…”

“…27 Remarkably, the positive role of PTP1B in cell motility was frequently associated with the stimulation of integrin-dependent signaling. 3,4,12,17,18,22 In contrast, the negative effect of PTP1B on cell motility was related to antagonizing signaling from growth factor receptor tyrosine kinases. [24][25][26][27] In a recent quantitative study, we analyzed the intrinsic motility and migration parameters of PTP1B-null cells (KO cells) in an isotropic 2-D fibronectin substratum.…”

MT1-MMP promotes cell growth and ERK activation through c-Src and paxillin in three-dimensional collagen matrix

“…When FAK is recruited to cell-matrix adhesion by binding with integrin-associated molecules such as talin and paxillin, it undergoes autophosphorylation at Tyr 397 and then associates with c-Src and phosphatidylinositol-3 kinase. c-Src phosphorylates Tyr 576 and 577 in the catalytic domain of FAK, which augments its kinase activity and induces the formation of a multimolecular complex, including Shc, JSAP1, and p130 Cas , leading to activate mitogen-activated protein kinases (MAPK) such as extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase [1][2][3][4]. In fact, elevated FAK and c-Src expression and activity has been associated with tumor progression [5].…”