Molecular Characterization of the Murine Cytotoxic T-Cell Membrane Glycoprotein Ly-3 (CD8)

• Published in: Proceedings of the National Academy of Sciences - PNAS 1987-10, Vol.84 (19), p.6874-6878
• Main Authors: Panaccio, Michael, Gillespie, Matthew T., Walker, Ian D., Kirszbaum, Louis, Sharpe, Jennifer A., Tobias, Glen H., Ian F. C. Mc Kenzie, Deacon, Nicholas J.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acids; Analysis of the immune response. Humoral and cellular immunity; Animals; Antigens; Antigens, Differentiation, T-Lymphocyte - genetics; Base Sequence; Biological and medical sciences; CDNA libraries; Cell Line; Cell Membrane - immunology; Cloning, Molecular; Complementary DNA; DNA - isolation & purification; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Immunobiology; Immunoglobulins; lymphocytes; lymphocytes T; Messenger RNA; Mice; Molecular Sequence Data; nucleotide sequence; Nucleotides; Organs and cells involved in the immune response; spleen; T lymphocytes; T-Lymphocytes, Cytotoxic - immunology; thymus; Untranslated regions
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.84.19.6874

The murine Ly-2/3 glycoprotein is a surface marker of T cells restricted by class I major histocompatibility complex antigens. It is a disulfide-bonded heterodimer in which either the α or α ′ polypeptide chain encoded by Ly-2 is covalently linked to the β polypeptide chain encoded by Ly-3. The nucleotide and predicted amino acid sequence of the murine Ly-3 cDNA, isolated by using the rat Ly-3 cDNA clone pX9.15, together with the amino acid sequence of Ly-3.1 peptides and the N terminus, are presented here. The alignment of peptide data from the Ly-3.1 antigen with that of the predicted amino acid sequence of the Ly-3.2 antigen confirmed that the putative Ly-3 cDNA clones do in fact encode the Ly-3 protein. The Ly-3.2 cDNA clones encode a protein of 213 amino acids, which includes a 21-residue leader sequence and structural features in common with immunoglobulin variable, joining, and hinge regions. Searches of protein data bases revealed that Ly-3 is a member of the immunoglobulin superfamily with significant homology to Ly-2, immunoglobulin variable region κ and λ light chains, and the β chain of the T-cell receptor. A single N-linked glycosylation site was found at asparagine-13. The relative expression of two mRNA species (approximately 1.3 and 2.3 kilobases) varied according to the source of mRNA. A murine B1 repeat was located in the 3′ untranslated region of Ly-3 cDNA clones.