Protein Tyrosine Phosphatase-PEST Regulates Focal Adhesion Disassembly, Migration, and Cytokinesis in Fibroblasts

Abstract

In this article, we show that, in transfected COS-1 cells, protein tyrosine phosphatase (PTP)-PEST translocates to the membrane periphery following stimulation by the extracellular matrix protein fibronectin. When plated on fibronectin, PTP-PEST (−/−) fibroblasts display a strong defect in motility. 3 h after plating on fibronectin, the number and size of vinculin containing focal adhesions were greatly increased in the homozygous PTP-PEST mutant cells as compared with heterozygous cells. This phenomenon appears to be due in part to a constitutive increase in tyrosine phosphorylation of p130CAS, a known PTP-PEST substrate, paxillin, which associates with PTP-PEST in vitro, and focal adhesion kinase (FAK). Another effect of this constitutive hyperphosphorylation, consistent with the focal adhesion regulation defect, is that (−/−) cells spread faster than the control cell line when plated on fibronectin. In the PTP-PEST (−/−) cells, an increase in affinity for the SH2 domains of Src and Crk towards p130CAS was also observed. In (−/−) cells, we found a significant increase in the level of tyrosine phosphorylation of PSTPIP, a cleavage furrow–associated protein that interacts physically with all PEST family members. An effect of PSTPIP hyperphosphorylation appears to be that some cells remain attached at the site of the cleavage furrow for an extended period of time. In conclusion, our data suggest PTP-PEST plays a dual role in cell cytoskeleton organization, by promoting the turnover of focal adhesions required for cell migration, and by directly or indirectly regulating the proline, serine, threonine phosphatase interacting protein (PSTPIP) tyrosine phosphorylation level which may be involved in regulating cleavage furrow formation or disassembly during normal cell division.

Low Expression of Tyrosine-protein Phosphatase Nonreceptor Type 12 is Associated with Lymph Node Metastasis and Poor Prognosis in Operable Triple-negative Breast Cancer

“…:http://dx.doi.org/10.7314/APJCP.2013.14.1.287 Low PTPN12 is Associated with Poor Prognosis in Operable Triple-negative Breast Cancer PTPN12 is also thought to play an important role in cell adhesion and motility, and is involved in cancer metastasis (Andersen et al, 2004;Streit et al, 2006;Hunter, 2009;Kwong et al, 2009;DeSantis et al, 2011;Rhee et al, 2012). To date, several researches reported that some oncogenes and cell adhesion molecules such like c-ABL, p130 (Cas), CAKbeta, and PSTPIP1 were associated with PTP family (Angers-Loustau et al, 1999;Andersen et al, 2004;Westbrook et al, 2008). Tingting Sun et al reported that PTPN12 suppressed transformation by interacting with and inhibiting tyrosine kinase signaling, such as EGFR and HER2.…”

A switch from p130Cas/Crk to Gab1/Crk signaling correlates with anchorage independent growth and JNK activation in cells transformed by the Met receptor oncoprotein

“…Absence of tyrosine phosphorylation of FAK, paxillin and p130Cas in Tpr-Met transformed cells may re¯ect a decrease in b1 integrin levels observed in TprMet transformed cells (data not shown) and the accompanying decrease in integrin dependent focal adhesions. Alternatively, since several phosphatases are involved in the dephosphorylation of FAK and associated focal adhesion proteins (Angers-Loustau et al, 1999;Yu et al, 1998), decreased tyrosine phosphorylation of focal adhesion proteins may re¯ect enhanced phosphatase activity. However, treatment of Tpr-Met transformed ®broblasts with tyrosine phosphatase inhibitors such as pervanadate or peroxovanadium failed to promote cell spreading (data not shown) and FAK tyrosine phosphorylation in pervanadate treated Tpr-Met transformed cells was signi®cantly reduced when compared with control Fr3T3 ®broblasts (data not shown).…”

TCR-induced downregulation of protein tyrosine phosphatase PEST augments secondary T cell responses

“…Wild-type and enzymatically-inactive mutant (C231S) of mouse PTP-PEST were cloned into the expression vectors pEF-BOS and pcDNA3.1 (Angers-Loustau et al, 1999). Human LYP, PTPH1, SHP1, LMPTP-B and HePTP cDNA in mammalian expression vector pEF5HA were described previously (Bottini et al, 2002;Brockdorff et al, 1999;Gjörloff-Wingren et al, 2000;Saxena et al, 1998;Vang et al, 2005).…”

“…In non-lymphoid cells, PTP-PEST participates in the dynamic regulation of focal adhesions, integrin signaling, and Rac-dependent motility (Angers-Loustau et al, 1999;Sastry et al, 2002). In B cells, PTP-PEST, was reported to reduce the phosphorylation of Shc, Pyk2, Fak, and Cas, and to inhibit activation of the Ras pathway (Davidson and Veillette, 2001).…”