Dynamic conformational changes in the FERM domain of FAK are involved in focal-adhesion behavior during cell spreading and motility.
Focal adhesion kinase (FAK) controls cellular adhesion and motility processes by its tight link to integrin- and extracellular-matrix-mediated signaling. To explore the dynamics of the regulation of FAK, we constructed a FRET-based probe that visualizes conformational rearrangements of the FERM domain of FAK in living cells. The sensor reports on an integrin-mediated conformational change in FAK following cellular adhesion. The perturbation is kinase-independent and involves the polybasic KAKTLR sequence in the FERM domain. It is manifested by an increased FRET signal and is expressed primarily in focal adhesions, and to a lesser extent in the cytoplasm. The conformational change in the FERM domain of FAK is observed in two consecutive phases during spreading - early and late - and is enriched in fully adhered motile cells at growing and sliding peripheral focal-adhesion sites, but not in stable or retracting focal adhesions. Inhibition of the actomyosin system indicates the involvement of tension signaling induced by Rho-associated kinase, rather than by myosin light-chain kinase, in the modulation of the FERM response. We conclude that the heterogeneous conformation of the FERM domain in focal adhesions of migrating cells reflects a complex regulatory mechanism for FAK that appears to be under the influence of cellular traction forces.
Papusheva
Ekaterina
E
Molecular Biology of Neuronal Signals, Max-Planck Institute of Experimental Medicine, 37075 Göttingen, Germany.
Mello de Queiroz
Fernanda
F
Dalous
Jeremie
J
Han
Yunyun
Y
Esposito
Alessandro
A
Jares-Erijmanxa
Elizabeth A
EA
Jovin
Thomas M
TM
Bunt
Gertrude
G
D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000378:metabolism*; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D022001:Focal Adhesions / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D011487:Protein Conformation; D015398:Signal Transduction / Q000502:physiology
D005456:Fluorescent Dyes; D051416:Focal Adhesion Protein-Tyrosine Kinases