title: Adhesive F-actin waves: a novel integrin-mediated adhesion complex coupled to ventral actin polymerization.
abstract: At the leading lamellipodium of migrating cells, protrusion of an Arp2/3-nucleated actin network is coupled to formation of integrin-based adhesions, suggesting that Arp2/3-mediated actin polymerization and integrin-dependent adhesion may be mechanistically linked. Arp2/3 also mediates actin polymerization in structures distinct from the lamellipodium, in "ventral F-actin waves" that propagate as spots and wavefronts along the ventral plasma membrane. Here we show that integrins engage the extracellular matrix downstream of ventral F-actin waves in several mammalian cell lines as well as in primary mouse embryonic fibroblasts. These "adhesive F-actin waves" require a cycle of integrin engagement and disengagement to the extracellular matrix for their formation and propagation, and exhibit morphometry and a hierarchical assembly and disassembly mechanism distinct from other integrin-containing structures. After Arp2/3-mediated actin polymerization, zyxin and VASP are co-recruited to adhesive F-actin waves, followed by paxillin and vinculin, and finally talin and integrin. Adhesive F-actin waves thus represent a previously uncharacterized integrin-based adhesion complex associated with Arp2/3-mediated actin polymerization.
authors: Department of Cell and Developmental Biology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America.
authors: Lindsay B
authors: LB
authors: Case
authors: Clare M
authors: CM
authors: Waterman
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D000818:Animals; D001859:Bone Neoplasms / Q000378:metabolism / Q000473:pathology; D002448:Cell Adhesion; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D008546:Melanoma, Experimental / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D012516:Osteosarcoma / Q000378:metabolism / Q000473:pathology; D051419:Paxillin / Q000378:metabolism; D016608:Talin / Q000378:metabolism; D016596:Vinculin / Q000378:metabolism*; D060589:Zyxin / Q000378:metabolism*
chemical_list: D051376:Actin-Related Protein 2-3 Complex; D000199:Actins; D016023:Integrins; D051419:Paxillin; D016608:Talin; D060589:Zyxin; D016596:Vinculin