Evidence from cDNA clones that the rat leukocyte-common antigen (T200) spans the lipid bilayer and contains a cytoplasmic domain of 80,000 Mr.
The leukocyte-common antigen (L-CA or T200) includes a family of lymphoid and myeloid cell surface glycoproteins with apparent molecular weights from 180,000 to 240,000. We report a partial protein sequence for thymocyte L-CA containing 1073 amino acids predicted from cDNA clones isolated using an oligonucleotide probe. Only one segment (residues 347-368) is likely to cross the membrane, and peptide data suggest that sequences N-terminal to this are outside the cell, with residues 369-1073 inside. The cytoplasmic domain includes possible phosphorylation sites and an internal homology between residues 385-671 and 676-986. Analysis of B lymphocyte cDNA clones suggests that B cell and thymocyte mRNAs are identical in 3' sequences, but size differences in Northern blots suggest 5' sequences may differ.
Thomas
M L
ML
Barclay
A N
AN
Gagnon
J
J
Williams
A F
AF
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D002462:Cell Membrane / Q000276:immunology; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000276:immunology*; D004247:DNA; D006649:Histocompatibility Antigens / Q000032:analysis* / Q000235:genetics / Q000302:isolation & purification; D017493:Leukocyte Common Antigens; D008051:Lipid Bilayers; D008954:Models, Biological; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D010766:Phosphorylation; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D013601:T-Lymphocytes / Q000276:immunology*
D006649:Histocompatibility Antigens; D008051:Lipid Bilayers; D012333:RNA, Messenger; D004247:DNA; D017493:Leukocyte Common Antigens