title: The primary structure of the beta-subunit of the cell surface adhesion glycoproteins LFA-1, CR3 and p150,95 and its relationship to the fibronectin receptor.
abstract: The lymphocyte-function-associated antigen-1 (LFA-1), the complement receptor type 3 (CR3) and the antigen p150,95 are cell-surface glycoproteins. They are heterodimeric complexes, each containing a unique alpha-subunit noncovalently associated with a common beta-subunit. We have purified the beta-subunit from human spleen and obtained limited peptide sequences. What appears to be the complete primary structure for the fully processed beta-subunit was obtained by cDNA sequencing of clones from a phorbol ester (PMA) stimulated U937 cDNA library. There are five possible glycosylation sites and a transmembrane segment. The sequence contains a high level of cysteine (7.6%), with 24 of the 57 cysteine residues being found in three repeating units each with eight residues. The entire primary structure has 47% identity to a subunit of a fibronectin binding protein from chicken fibroblasts. It seems that LFA-1, CR3 and p150,95 antigens may belong to an extended family of cell surface molecules including the fibronectin binding protein.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis; D005353:Fibronectins / Q000378:metabolism; D005796:Genes; D006801:Humans; D016169:Lymphocyte Function-Associated Antigen-1; D046911:Macromolecular Substances; D016177:Macrophage-1 Antigen; D011951:Receptors, Complement / Q000235:genetics*; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic / Q000235:genetics*; D013154:Spleen / Q000276:immunology / Q000378:metabolism
chemical_list: D000954:Antigens, Surface; D005353:Fibronectins; D016169:Lymphocyte Function-Associated Antigen-1; D046911:Macromolecular Substances; D016177:Macrophage-1 Antigen; D011951:Receptors, Complement; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic; D004247:DNA