The lymphocyte glycoprotein CD6 contains a repeated domain structure characteristic of a new family of cell surface and secreted proteins

• Published in: The Journal of experimental medicine Vol. 174; no. 4; pp. 949 - 952
• Main Authors: ARUFFO, A, MELNICK, M. B, LINSLEY, P. S, SEED, B
• Format: Journal Article
• Language: English
• Published: New York, NY Rockefeller University Press 01.10.1991; The Rockefeller University Press
• Subjects: Amino Acid Sequence; Animals; Antigens, CD - genetics; Antigens, Differentiation, T-Lymphocyte - genetics; Antigens, Surface - genetics; Biological and medical sciences; DNA, Neoplasm - genetics; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Gene Library; Humans; Immunobiology; Lymphocytes - immunology; Lymphoid cells: ontogeny, maturation, markers, receptors, circulation and recirculation; Membrane Glycoproteins - genetics; Molecular Sequence Data; Precursor Cell Lymphoblastic Leukemia-Lymphoma - genetics; Precursor Cell Lymphoblastic Leukemia-Lymphoma - immunology; Repetitive Sequences, Nucleic Acid; Sequence Homology, Nucleic Acid; Transfection; Human; Complementary DNA; Molecular structure; Sequence alignment; T-Lymphocyte; Biological marker; Glycoproteins; Structure function relationship; Cell surface
• ISSN: 0022-1007; 1540-9538
• DOI: 10.1084/jem.174.4.949

The isolation, characterization, and expression of a full-length cDNA encoding the human T cell glycoprotein CD6 is described. COS cells transfected with the CD6 clone express a 90-kD protein that reacts with all available anti-CD6 monoclonal antibodies. RNA blot hybridization analysis indicates that CD6 transcripts are predominantly restricted to cells in the T lineage. The predicted CD6 sequence is 468 amino acids long, with the typical features of a type I integral membrane protein. The cytoplasmic domain of CD6 contains two serine residues, one or both of which are substrates for phosphorylation during T cell activation. The extracellular domain of CD6 is significantly related to the extracellular domain of the human and mouse T cell antigen CD5, the cysteine-rich domain of the bovine and mouse type I macrophage scavenger receptor, the extracellular domain of the sea urchin spermatozoa protein that crosslinks the egg peptide speract, the mammalian complement factor 1, and the human lung tumor antigen L3. These molecules, therefore, constitute a new gene superfamily that is well conserved across species boundaries.