Integrins alpha v beta 3 and alpha v beta 5 contribute to cell attachment to vitronectin but differentially distribute on the cell surface.
We investigated the role of the integrins alpha v beta 3 and alpha v beta 5 in mediating vitronectin adhesion of three phenotypically distinct cell types. M21 human melanoma cells and H2981 lung carcinoma cells use both alpha v-containing integrins in adhering to vitronectin while UCLA-P3 lung carcinoma cells adhere exclusively with alpha v beta 5. Specifically, monoclonal antibodies directed to functional epitopes on both receptors were required to block adhesion of M21 or H2981 cells while adhesion of UCLA-P3 cells to vitronectin could be blocked with a monoclonal antibody to alpha v beta 5. Although both receptors are involved in M21 and H2981 cell adhesion to vitronectin, only alpha v beta 3 can be detected in focal contacts, colocalizing with vinculin, talin, and the ends of actin filaments, while alpha v beta 5 shows a distinct, nonfocal contact, distribution on the cell surface. These results provide the first evidence that two homologous integrins that recognize the same ligand distribute differentially on the cell surface.
Wayner
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EA
Oncogen, Seattle, Washington 98121.
Orlando
R A
RA
Cheresh
D A
DA
D008841:Actin Cytoskeleton / Q000648:ultrastructure; D000199:Actins / Q000378:metabolism; D000911:Antibodies, Monoclonal / Q000276:immunology; D002448:Cell Adhesion; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000648:ultrastructure; D003598:Cytoskeletal Proteins / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D016023:Integrins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D008970:Molecular Weight; D011233:Precipitin Tests; D011971:Receptors, Immunologic / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D019030:Receptors, Vitronectin; D016608:Talin; D014407:Tumor Cells, Cultured; D016596:Vinculin; D019096:Vitronectin
D000199:Actins; D000911:Antibodies, Monoclonal; D003598:Cytoskeletal Proteins; D006023:Glycoproteins; D016023:Integrins; D011971:Receptors, Immunologic; D019030:Receptors, Vitronectin; D016608:Talin; D019096:Vitronectin; D016596:Vinculin