title: PyK2 and FAK connections to p190Rho guanine nucleotide exchange factor regulate RhoA activity, focal adhesion formation, and cell motility.
abstract: Integrin binding to matrix proteins such as fibronectin (FN) leads to formation of focal adhesion (FA) cellular contact sites that regulate migration. RhoA GTPases facilitate FA formation, yet FA-associated RhoA-specific guanine nucleotide exchange factors (GEFs) remain unknown. Here, we show that proline-rich kinase-2 (Pyk2) levels increase upon loss of focal adhesion kinase (FAK) in mouse embryonic fibroblasts (MEFs). Additionally, we demonstrate that Pyk2 facilitates deregulated RhoA activation, elevated FA formation, and enhanced cell proliferation by promoting p190RhoGEF expression. In normal MEFs, p190RhoGEF knockdown inhibits FN-associated RhoA activation, FA formation, and cell migration. Knockdown of p190RhoGEF-related GEFH1 does not affect FA formation in FAK(-/-) or normal MEFs. p190RhoGEF overexpression enhances RhoA activation and FA formation in MEFs dependent on FAK binding and associated with p190RhoGEF FA recruitment and tyrosine phosphorylation. These studies elucidate a compensatory function for Pyk2 upon FAK loss and identify the FAK-p190RhoGEF complex as an important integrin-proximal regulator of FA formation during FN-stimulated cell motility.
authors.affiliation: Department of Reproductive Medicine, Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: Yangmi
authors.initials: Y
authors.lastname: Lim
authors.forename: Ssang-Taek
authors.initials: ST
authors.lastname: Lim
authors.forename: Alok
authors.initials: A
authors.lastname: Tomar
authors.forename: Margaret
authors.initials: M
authors.lastname: Gardel
authors.forename: Joie A
authors.initials: JA
authors.lastname: Bernard-Trifilo
authors.forename: Xiao Lei
authors.initials: XL
authors.lastname: Chen
authors.forename: Sean A
authors.initials: SA
authors.lastname: Uryu
authors.forename: Rafaela
authors.initials: R
authors.lastname: Canete-Soler
authors.forename: Jinbin
authors.initials: J
authors.lastname: Zhai
authors.forename: Hong
authors.initials: H
authors.lastname: Lin
authors.forename: William W
authors.initials: WW
authors.lastname: Schlaepfer
authors.forename: Perihan
authors.initials: P
authors.lastname: Nalbant
authors.forename: Gary
authors.initials: G
authors.lastname: Bokoch
authors.forename: Dusko
authors.initials: D
authors.lastname: Ilic
authors.forename: Clare
authors.initials: C
authors.lastname: Waterman-Storer
authors.forename: David D
authors.initials: DD
authors.lastname: Schlaepfer
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D049109:Cell Proliferation; D051417:Focal Adhesion Kinase 1 / Q000235:genetics / Q000378:metabolism*; D051418:Focal Adhesion Kinase 2 / Q000235:genetics / Q000378:metabolism*; D022001:Focal Adhesions / Q000502:physiology*; D005786:Gene Expression Regulation; D051379:Mice; D051419:Paxillin / Q000378:metabolism; D010766:Phosphorylation; D014443:Tyrosine / Q000378:metabolism; D020666:ras-GRF1 / Q000235:genetics / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
chemical_list: D051419:Paxillin; C513037:Rasgrf1 protein, mouse; D020666:ras-GRF1; D014443:Tyrosine; D051417:Focal Adhesion Kinase 1; D051418:Focal Adhesion Kinase 2; C496051:Ptk2 protein, mouse; C496053:Ptk2b protein, mouse; D020742:rhoA GTP-Binding Protein