Talin1 is critical for force-dependent reinforcement of initial integrin-cytoskeleton bonds but not tyrosine kinase activation.
Cells rapidly transduce forces exerted on extracellular matrix contacts into tyrosine kinase activation and recruitment of cytoskeletal proteins to reinforce integrin-cytoskeleton connections and initiate adhesion site formation. The relationship between these two processes has not been defined, particularly at the submicrometer level. Using talin1-deficient cells, it appears that talin1 is critical for building early mechanical linkages. Deletion of talin1 blocked laser tweezers, force-dependent reinforcement of submicrometer fibronectin-coated beads and early formation of adhesion sites in response to force, even though Src family kinases, focal adhesion kinase, and spreading were activated normally. Recruitment of vinculin and paxillin to sites of force application also required talin1. FilaminA had a secondary role in strengthening fibronectin-integrin-cytoskeleton connections and no role in stretch-dependent adhesion site assembly. Thus, force-dependent activation of tyrosine kinases is independent of early force-dependent structural changes that require talin1 as part of a critical scaffold.
Department of Biological Sciences, Columbia University, New York, NY 10027, USA. ms2001@columbia.edu
Grégory
G
Giannone
Guoying
G
Jiang
Deborah H
DH
Sutton
David R
DR
Critchley
Michael P
MP
Sheetz
D002448:Cell Adhesion / Q000235:genetics; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002460:Cell Line; D002461:Cell Line, Transformed; D003285:Contractile Proteins / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism*; D004789:Enzyme Activation; D005353:Fibronectins / Q000378:metabolism; D064448:Filamins; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D022001:Focal Adhesions / Q000378:metabolism; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D008545:Melanoma / Q000473:pathology; D008840:Microfilament Proteins / Q000378:metabolism; D008954:Models, Biological; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D013314:Stress, Mechanical; D016608:Talin / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D016596:Vinculin / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism
D015815:Cell Adhesion Molecules; D003285:Contractile Proteins; D003598:Cytoskeletal Proteins; D005353:Fibronectins; D064448:Filamins; D016023:Integrins; D008840:Microfilament Proteins; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D016608:Talin; D016596:Vinculin; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D019061:src-Family Kinases