title: The very late antigen family of heterodimers is part of a superfamily of molecules involved in adhesion and embryogenesis.
abstract: The very late antigen (VLA) protein family contains at least five related heterodimers, including a fibronectin receptor structure, and probably other cell substrate adhesion receptors. These cell-surface VLA proteins were immunopurified from human placenta (VLA-1, VLA-3, and VLA-5), platelets (VLA-2), and Molt-4 cells (VLA-4) using a series of monoclonal antibody-Sepharose immunoaffinity columns. After further purification by gel electrophoresis, the N-terminal amino acid sequence for each of the five VLA alpha subunits was determined. In the first 14 positions, the five VLA alpha subunits showed an average of 42% homology to each other, rising to 59% including conservative amino acid substitutions. In addition, the alpha subunits from the LFA-1, Mac-1 (CR-3), and p150,95 family of heterodimers, the vitronectin receptor-platelet GPIIb/IIIa family, and a position-specific (PS) antigen important in Drosophila embryogenesis each showed average homologies of 31-40% to individual VLA alpha sequences and 46-52% homology to VLA alpha subunits including conservative substitutions. Taken together, these results suggest that the VLA proteins, the LFA-1, Mac-1, and p150,95 family, the GPIIb/IIIa, vitronectin receptor family, and the Drosophila PS antigens have evolved as four subgroups in a highly conserved supergene family of receptors involved in fundamentally important functions, such as cell adhesion, migration, and embryogenesis.
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000235:genetics* / Q000302:isolation & purification; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules; D004622:Embryo, Mammalian; D005260:Female; D006801:Humans; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000235:genetics*; D010920:Placenta; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; D046911:Macromolecular Substances; D008565:Membrane Proteins; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7