Regulation of focal adhesion kinase by a novel protein inhibitor FIP200.
Focal adhesion kinase (FAK) is a major mediator of integrin signaling pathways. The mechanisms of regulation of FAK activity and its associated cellular functions are not very well understood. Here, we present data suggesting that a novel protein FIP200 functions as an inhibitor for FAK. We show the association of endogenous FIP200 with FAK, which is decreased upon integrin-mediated cell adhesion concomitant with FAK activation. In vitro- and in vivo-binding studies indicate that FIP200 interacts with FAK through multiple domains directly. FIP200 bound to the kinase domain of FAK inhibited its kinase activity in vitro and its autophosphorylation in vivo. Overexpression of FIP200 or its segments inhibited cell spreading, cell migration, and cell cycle progression, which correlated with their inhibition of FAK activity in vivo. The inhibition of these cellular functions by FIP200 could be rescued by coexpression of FAK. Last, we show that disruption of the functional interaction between endogenous FIP200 with FAK leads to increased FAK phosphorylation and partial restoration of cell cycle progression in cells plated on poly-L-lysine, providing further support for FIP200 as a negative regulator of FAK. Together, these results identify FIP200 as a novel protein inhibitor for FAK.
Abbi
Smita
S
Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
Ueda
Hiroki
H
Zheng
Chuanhai
C
Cooper
Lee Ann
LA
Zhao
Jihe
J
Christopher
Renee
R
Guan
Jun-Lin
JL
D016475:3T3 Cells; D000818:Animals; D000071183:Autophagy-Related Proteins; D015153:Blotting, Western; D001973:Bromodeoxyuridine / Q000494:pharmacology; D016466:CHO Cells; D002448:Cell Adhesion; D002453:Cell Cycle; D002465:Cell Movement; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000378:metabolism; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D005822:Genetic Vectors; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism* / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction
D000071183:Autophagy-Related Proteins; C407704:RB1CC1 protein, human; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496051:Ptk2 protein, mouse; D001973:Bromodeoxyuridine; D005978:Glutathione