Characterization of PINCH-2, a new focal adhesion protein that regulates the PINCH-1-ILK interaction, cell spreading, and migration.
Integrin-linked kinase (ILK) is a multidomain protein that plays important roles at cell-extracellular matrix (ECM) adhesion sites. We describe here a new LIM-domain containing protein (termed as PINCH-2) that forms a complex with ILK. PINCH-2 is co-expressed with PINCH-1 (previously known as PINCH), another member of the PINCH protein family, in a variety of human cells. Immunofluorescent staining of cells with PINCH-2-specific antibodies show that PINCH-2 localizes to both cell-ECM contact sites and the nucleus. Deletion of the first LIM (LIM1) domain of PINCH-2 abolished the ability of PINCH-2 to form a complex with ILK. The ILK-binding defective LIM1-deletion mutant, unlike the wild type PINCH-2 or the ILK-binding competent LIM5-deletion mutant, was incapable of localizing to cell-ECM contact sites, suggesting that ILK binding is required for this process. Importantly, the PINCH-2-ILK and PINCH-1-ILK interactions are mutually exclusive. Overexpression of PINCH-2 significantly inhibited the PINCH-1-ILK interaction and reduced cell spreading and migration. These results identify a novel nuclear and focal adhesion protein that associates with ILK and reveals an important role of PINCH-2 in the regulation of the PINCH-1-ILK interaction, cell shape change, and migration.
Zhang
Yongjun
Y
Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
Chen
Ka
K
Guo
Lida
L
Wu
Chuanyue
C
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000502:physiology; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology*; D048429:Cell Size; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D022001:Focal Adhesions / Q000737:chemistry* / Q000378:metabolism; D017930:Genes, Reporter; D006801:Humans; D007150:Immunohistochemistry; D060588:LIM Domain Proteins; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D000099200:Scaffold Protein ILK
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D060588:LIM Domain Proteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; D017346:Protein Serine-Threonine Kinases; D011993:Recombinant Fusion Proteins; D000099200:Scaffold Protein ILK; C088088:LIMS1 protein, human; C490235:LIMS2 protein, human; C490232:Lims1 protein, mouse; C490234:Lims2 protein, mouse