Exceptionally high conservation of the MHC class I-related gene, MR1, among mammals

Kentaro Tsukamoto, Janine Deakin, Jennifer Marshall Graves, Keiichiro Hashimoto

Research output: Contribution to journalArticle

49 Citations (Scopus)

Abstract

The major histocompatibility complex (MHC) class I-related gene, MR1, is a non-classical MHC class IA gene and is encoded outside the MHC region. The MR1 is responsible for activation of mucosal-associated invariant T (MAIT) cells expressing semi-invariant T cell receptors in the presence of bacteria, but its ligand has not been identified. A unique characteristic of MR1 is its high evolutionary conservation of the a1 and a2 domains corresponding to the peptide-binding domains of classical MHC class I molecules, showing about 90 % amino acid identity between human and mouse. To clarify the evolutionary history of MR1 and identify more critically conserved residues for the function of MR1, we searched for the MR1 gene using jawed vertebrate genome databases and isolated the MR1 cDNA sequences of marsupials (opossum and wallaby). A comparative genomic analysis indicated that MR1 is only present in placental and marsupial mammals and that the gene organization around MR1 is well conserved among analyzed jawed vertebrates. Moreover, the a1 and a2 domains, especially in amino acid residues presumably shaping a ligand-binding groove, were also highly conserved between placental and marsupial MR1. These findings suggest that the MR1 gene might have been established at its present location in a common ancestor of placental and marsupial mammals and that the shape of the putative ligand-binding groove in MR1 has been maintained, probably for presenting highly conserved component(s) of microbes to MAIT cells.
Original languageEnglish
Pages (from-to)115-124
Number of pages10
JournalImmunogenetics
Volume65
DOIs
Publication statusPublished - 2013
Externally publishedYes

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MHC Class I Genes
Marsupialia
Major Histocompatibility Complex
Mammals
Ligands
Genes
Vertebrates
Macropodidae
Opossums
Amino Acids
T-Cell Antigen Receptor
Complementary DNA
History
Genome
Databases
Bacteria
Mucosal-Associated Invariant T Cells

Cite this

Tsukamoto, Kentaro ; Deakin, Janine ; Marshall Graves, Jennifer ; Hashimoto, Keiichiro. / Exceptionally high conservation of the MHC class I-related gene, MR1, among mammals. In: Immunogenetics. 2013 ; Vol. 65. pp. 115-124.
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Exceptionally high conservation of the MHC class I-related gene, MR1, among mammals. / Tsukamoto, Kentaro; Deakin, Janine; Marshall Graves, Jennifer; Hashimoto, Keiichiro.

In: Immunogenetics, Vol. 65, 2013, p. 115-124.

Research output: Contribution to journalArticle

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