Extracellular matrix receptors, ECMRII and ECMRI, for collagen and fibronectin correspond to VLA-2 and VLA-3 in the VLA family of heterodimers.
The Very Late Activation Antigen (VLA) proteins are a family of five related heterodimers, which also are part of the integrin superfamily of cell adhesion molecules. Except for the identification of VLA-5 as a fibronectin receptor structure, the functions of the VLA proteins have remained unclarified. In this paper, immunoprecipitation experiments with both anti-alpha and anti-beta subunit antibodies showed that the previously identified cell adhesion receptor for collagen, extracellular matrix receptor II (ECMRII), is equivalent to VLA-2. At the same time a previously described multispecific cell adhesion receptor for collagen, fibronectin, and laminin (ECMRI) has been shown to be identical to VLA-3. Although the mAb 12F1 and P1H5 both recognized VLA-2 (ECMRII), they appeared to define distinct epitopes on the alpha 2 subunit. On the other hand, the mAb P1B5 and J143 recognized the alpha 3 subunit of VLA-3 (ECMRI) at or near the same site. Consistent with the collagen receptor functions of VLA-2 (ECMRII) and VLA-3 (ECMRI), anti-VLA beta antiserum blocked cell attachment to collagen.
Takada
Y
Y
Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115.
Wayner
E A
EA
Carter
W G
WG
Hemler
M E
ME
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000032:analysis*; D001792:Blood Platelets / Q000276:immunology; D002448:Cell Adhesion; D002460:Cell Line; D003094:Collagen / Q000378:metabolism*; D000939:Epitopes / Q000032:analysis; D005109:Extracellular Matrix / Q000276:immunology / Q000378:metabolism*; D005260:Female; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D010920:Placenta / Q000276:immunology; D011247:Pregnancy; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D011956:Receptors, Cell Surface / Q000276:immunology / Q000378:metabolism*; D038981:Receptors, Collagen; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D000939:Epitopes; D005353:Fibronectins; D011948:Receptors, Antigen, T-Cell; D011956:Receptors, Cell Surface; D038981:Receptors, Collagen; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D003094:Collagen