Human leukocyte activation antigen M6, a member of the Ig superfamily, is the species homologue of rat OX-47, mouse basigin, and chicken HT7 molecule.
Peripheral granulocytes from rheumatoid arthritis and reactive arthritis patients were recently found to express higher levels of a newly defined Ag, termed M6, in comparison to granulocytes from healthy subjects. We present here the molecular characterization of M6 Ag and show that it is a novel human leukocyte activation-associated cell surface glycoprotein. Peripheral lymphocytes do not significantly express M6 Ag, however, it appears upon 3-day PHA-activated T blasts. On monocytes, which constitutively express M6 Ag, it is down-regulated on day 1 but re-induced on day 3 of granulocyte-macrophage CSF stimulation. SDS-PAGE analysis of M6 immunoprecipitates shows a single band of 54 kDa under nonreducing conditions that shifts to 65 kDa under reducing conditions. Endoglycosidase F treatment of M6 immunoprecipitate reveals that 50% of the M6 molecule is composed of N-linked carbohydrates. By modifying the COS cell cloning strategy, we have isolated cDNA clones encoding M6 Ag. M6 cDNA hybridizes with a single mRNA transcript of approximately 1.7 kb in Northern blotting. Comparison analysis of the M6 sequence indicates that M6 Ag is a member of the Ig superfamily and the species homologue of rat OX-47 Ag, mouse basigin (gp42), and chicken HT7 molecule. The highly conserved remarkable transmembrane domain suggests that the M6 Ag may be a component of a multichain complex in the plasma membrane.
Kasinrerk
W
W
Institute of Immunology-Vienna International Research Cooperation Center, Sandoz Forschungsinstitut, Austria.
Fiebiger
E
E
Stefanová
I
I
Baumruker
T
T
Knapp
W
W
Stockinger
H
H
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface / Q000737:chemistry / Q000235:genetics*; D030161:Avian Proteins; D001483:Base Sequence; D051926:Basigin; D001798:Blood Proteins; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D006023:Glycoproteins / Q000235:genetics*; D006801:Humans; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D005810:Multigene Family; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D030161:Avian Proteins; C497886:BSG protein, human; D001798:Blood Proteins; C102624:Bsg protein, Gallus gallus; C079432:Bsg protein, rat; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D051926:Basigin; D004247:DNA