The integrin-linked kinase regulates cell morphology and motility in a rho-associated kinase-dependent manner.
The integrin-linked kinase (ILK) is a multidomain focal adhesion protein implicated in signal transmission from integrin and growth factor receptors. We have determined that ILK regulates U2OS osteosarcoma cell spreading and motility in a manner requiring both kinase activity and localization. Overexpression of wild-type (WT) ILK resulted in suppression of cell spreading, polarization, and motility to fibronectin. Cell lines overexpressing kinase-dead (S343A) or paxillin binding site mutant ILK proteins display inhibited haptotaxis to fibronectin. Conversely, spreading and motility was potentiated in cells expressing the "dominant negative," non-targeting, kinase-deficient E359K ILK protein. Suppression of cell spreading and motility of WT ILK U2OS cells could be rescued by treatment with the Rho-associated kinase (ROCK) inhibitor Y-27632 or introduction of dominant negative ROCK or RhoA, suggesting these cells have increased RhoA signaling. Activation of focal adhesion kinase (FAK), a negative regulator of RhoA, was reduced in WT ILK cells, whereas overexpression of FAK rescued the observed defects in spreading and cell polarity. Thus, ILK-dependent effects on ROCK and/or RhoA signaling may be mediated through FAK.
Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York 13210, USA.
Wara A K M
WA
Khyrul
David P
DP
LaLonde
Michael C
MC
Brown
Howard
H
Levinson
Christopher E
CE
Turner
D000577:Amides / Q000494:pharmacology; D002465:Cell Movement / Q000502:physiology*; D016764:Cell Polarity; D002477:Cells / Q000166:cytology*; D002633:Chemotaxis; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005353:Fibronectins; D005455:Fluorescent Antibody Technique; D051416:Focal Adhesion Protein-Tyrosine Kinases; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins; D016296:Mutagenesis; D012516:Osteosarcoma; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000032:analysis / Q000235:genetics / Q000502:physiology; D011725:Pyridines / Q000494:pharmacology; D011993:Recombinant Fusion Proteins; D015398:Signal Transduction; D014162:Transfection; D014407:Tumor Cells, Cultured; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000502:physiology; D000099200:Scaffold Protein ILK
D000577:Amides; D004791:Enzyme Inhibitors; D005353:Fibronectins; D051416:Focal Adhesion Protein-Tyrosine Kinases; D049452:Green Fluorescent Proteins; D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases; D011725:Pyridines; D011993:Recombinant Fusion Proteins; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein; D000099200:Scaffold Protein ILK; C108830:Y 27632