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De novo expression of pp125 FAK in human macrophages regulates CSK distribution and MAP kinase activation but does not affect focal contact structure
Author(s) -
De Nichilo Mark O.,
Katz BenZion,
O'Connell Brian,
Yamada Kenneth M.
Publication year - 1999
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/(sici)1097-4652(199902)178:2<164::aid-jcp5>3.0.co;2-r
Subject(s) - focal adhesion , paxillin , ptk2 , proto oncogene tyrosine protein kinase src , microbiology and biotechnology , tyrosine phosphorylation , tyrosine kinase , phosphorylation , biology , tyrosine , integrin , signal transduction , cell , protein kinase a , biochemistry , mitogen activated protein kinase kinase
The protein tyrosine kinase pp125 FAK (focal adhesion kinase, or FAK) is expressed by a variety of cell types and has been implicated in integrin‐mediated signaling events. We explored the potential functions of FAK by expressing it de novo in a cell type lacking FAK. We showed previously that cultured human macrophages lack FAK yet still have well‐formed focal contacts. Adenovirus‐mediated expression of FAK results in the appearance of FAK protein, which localizes to focal contacts and becomes tyrosine‐phosphorylated without perturbing overall cell morphology or focal contacts. FAK associates with CSK 48 h after infection and recruits it to focal contacts. Tyrosine phosphorylation of p130 cas but not of paxillin is stimulated after FAK expression. The phosphorylation of p130 cas is lost at 48 h in parallel with CSK accumulation in focal contacts. The ERK2 form of MAP kinase is similarly activated at 12–24 h, but it also returns to low levels at 48 h. These findings demonstrate that FAK can be reconstituted to focal contacts in cells that lack it without affecting cell morphology or focal contact structure. FAK can regulate the distribution and activities of elements of the MAP kinase signaling pathway. J Cell Physiol 178:164–172, 1999. Published 1999 Wiley‐Liss, Inc.