title: HLA-A2 and HLA-B7 antigens are phosphorylated in vitro by rous sarcoma virus kinase (pp60v-src) at a tyrosine residue encoded in a highly conserved exon of the intracellular domain.
abstract: HLA-A2 and -B7 antigens are phosphorylated by Rous sarcoma kinase (pp60v-src) in vitro. The phosphate group is attached to the heavy chains as determined by NaDodSO4/polyacrylamide gel electrophoresis. The site of phosphorylation was localized to the COOH-terminal intracellular domain by its susceptibility to limited trypsin proteolysis. Furthermore, the 32P-labeled amino acid is a single tyrosine residue located in the COOH terminus of the heavy chain. The protein sequences of known class I human and murine intracellular domains contain a highly conserved sequence -K-G-G-X-Y- located NH2-terminally to the single tyrosine residue of this domain. The DNA sequences that encode class I antigen intracellular domains were compared by computer with a homology matrix program. Exon 6 which encodes the conserved tyrosine-containing protein sequence in both human and mouse is 75% homologous across species and 90-100% homologous within species. The significance of the high degree of conservation within exon 6 is discussed.
mesh_terms: D000595:Amino Acid Sequence; D001358:Avian Sarcoma Viruses / Q000201:enzymology*; D001483:Base Sequence; D006680:HLA Antigens / Q000235:genetics / Q000378:metabolism*; D015789:HLA-A2 Antigen; D015793:HLA-B7 Antigen; D006801:Humans; D015688:Oncogene Protein pp60(v-src); D010766:Phosphorylation; D014443:Tyrosine / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D006680:HLA Antigens; D015789:HLA-A2 Antigen; D015793:HLA-B7 Antigen; D014764:Viral Proteins; D014443:Tyrosine; D015688:Oncogene Protein pp60(v-src)