TY - JOUR
T1 - Murine MHC class Ib gene, H2-M2, encodes a conserved surface-expressed glycoprotein
AU - Moore, Yuki F.
AU - Lambracht-Washington, Doris
AU - Tabaczewski, Piotr
AU - Lindahl, Kirsten Fischer
N1 - Funding Information:
Acknowledgements We thank Iwona Stroynowski, Attila Kum - novics, and Toyoyuki Takada for helpful discussions, Tiencia Dupass for technical assistance, and Olga Zagnitko, Teresa Bannister and Clive Slaughter of the Howard Hughes Biopolymer Facility for DNA sequencing. This work was supported in part by NIH grant AI 37818.
PY - 2004/4
Y1 - 2004/4
N2 - We have determined the genomic sequence of H2-M2 in seven haplotypes from nine inbred strains of mice and in five wild-derived haplotypes. Except for the spretus haplotype sp1 with a premature stop codon, we found only limited polymorphism. Four of the five amino acid substitutions in the a-helices are at positions that would point out from the antigen-binding groove, indicating that the polymorphism might influence receptor recognition rather than antigen binding. The rat homologue, RTI.M2lv1, has 89% identity to H2-M2 at the nucleotide level and 91% at the amino acid level, and it also encodes an intact MHC class I glycoprotein. Chimeric proteins with α 1α2 or α3-transmembrane domains encoded by H2-Q9 were detectable on the surface of transfectants with monoclonal antibodies against Qa2, and the full-length M2 protein, labeled by fusion with green fluorescent protein, was detectable with S 19.8 monoclonal antibodies. The H2-M2 protein was thus expressed on the cell surface, even in TAP-deficient RMA-S cells at 37°C, suggesting that it is TAP-independent. We conclude that H2-M2 is a conserved mouse class Ib gene that is translated to a surface-expressed MHC class I molecule with a function still to be elucidated.
AB - We have determined the genomic sequence of H2-M2 in seven haplotypes from nine inbred strains of mice and in five wild-derived haplotypes. Except for the spretus haplotype sp1 with a premature stop codon, we found only limited polymorphism. Four of the five amino acid substitutions in the a-helices are at positions that would point out from the antigen-binding groove, indicating that the polymorphism might influence receptor recognition rather than antigen binding. The rat homologue, RTI.M2lv1, has 89% identity to H2-M2 at the nucleotide level and 91% at the amino acid level, and it also encodes an intact MHC class I glycoprotein. Chimeric proteins with α 1α2 or α3-transmembrane domains encoded by H2-Q9 were detectable on the surface of transfectants with monoclonal antibodies against Qa2, and the full-length M2 protein, labeled by fusion with green fluorescent protein, was detectable with S 19.8 monoclonal antibodies. The H2-M2 protein was thus expressed on the cell surface, even in TAP-deficient RMA-S cells at 37°C, suggesting that it is TAP-independent. We conclude that H2-M2 is a conserved mouse class Ib gene that is translated to a surface-expressed MHC class I molecule with a function still to be elucidated.
KW - Cell surface molecules
KW - Major histocompatibility complex
KW - Mouse
KW - Non-classical class I gene
KW - Rat
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U2 - 10.1007/s00251-004-0661-6
DO - 10.1007/s00251-004-0661-6
M3 - Article
C2 - 15045471
AN - SCOPUS:2442543353
SN - 0093-7711
VL - 56
SP - 1
EP - 11
JO - Immunogenetics
JF - Immunogenetics
IS - 1
ER -