Murine MHC class Ib gene, H2-M2, encodes a conserved surface-expressed glycoprotein

Immunogenetics. 2004 Apr;56(1):1-11. doi: 10.1007/s00251-004-0661-6. Epub 2004 Mar 26.

Abstract

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 alpha-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, RT1.M2(lv1), 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 alpha(1)alpha(2) or alpha(3)-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 S19.8 monoclonal antibodies. The H2-M2 protein was thus expressed on the cell surface, even in TAP-deficient RMA-S cells at 37 degrees 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.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alternative Splicing
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • Conserved Sequence
  • DNA, Complementary / genetics
  • Genes, MHC Class I*
  • HeLa Cells
  • Histocompatibility Antigens / genetics
  • Histocompatibility Antigens Class II / genetics*
  • Humans
  • Membrane Glycoproteins / genetics*
  • Membrane Glycoproteins / immunology*
  • Mice
  • Mice, Inbred Strains
  • Molecular Sequence Data
  • Phylogeny
  • Polymorphism, Genetic
  • Rats
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / immunology
  • Sequence Homology, Amino Acid
  • Transfection

Substances

  • DNA, Complementary
  • H2-M antigens
  • Histocompatibility Antigens
  • Histocompatibility Antigens Class II
  • Membrane Glycoproteins
  • Recombinant Fusion Proteins
  • histocompatibility antigens RT, rat

Associated data

  • GENBANK/AY302188
  • GENBANK/AY302189
  • GENBANK/AY302190
  • GENBANK/AY302191
  • GENBANK/AY302192
  • GENBANK/AY302193
  • GENBANK/AY302194
  • GENBANK/AY302195
  • GENBANK/AY302196
  • GENBANK/AY302197
  • GENBANK/AY302198
  • GENBANK/AY302199
  • GENBANK/AY302200
  • GENBANK/AY302201
  • GENBANK/AY302202
  • GENBANK/AY302203
  • GENBANK/AY302204
  • GENBANK/AY302205
  • GENBANK/AY302206
  • GENBANK/AY302207
  • GENBANK/AY302208
  • GENBANK/AY302209
  • GENBANK/AY302210
  • GENBANK/AY302211
  • GENBANK/AY302212
  • GENBANK/AY302213
  • GENBANK/AY302214
  • GENBANK/AY302215
  • GENBANK/AY302216
  • GENBANK/AY302217
  • GENBANK/AY302218
  • GENBANK/AY326271
  • GENBANK/AY327254