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

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 80; no. 10; pp. 2894 - 2898
• Main Authors: Guild, Braydon C., Erikson, Raymond L., Strominger, Jack L.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 01.05.1983; National Acad Sciences
• Subjects: Amino Acid Sequence; Amino acids; Antigens; Avian Sarcoma Viruses - enzymology; Base Sequence; Exons; Gels; Histocompatibility antigens class I; HLA antigens; HLA Antigens - genetics; HLA Antigens - metabolism; HLA-A2 Antigen; HLA-B7 Antigen; Humans; Mice; Nucleotide sequences; Nucleotides; Oncogene Protein pp60(v-src); Phosphorylation; Rous sarcoma virus; Tyrosine - metabolism; Viral Proteins - metabolism
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.80.10.2894

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, the32P-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.