| First Author | Riegert P | Year | 1998 |
| Journal | J Immunol | Volume | 161 |
| Issue | 8 | Pages | 4066-77 |
| PubMed ID | 9780177 | Mgi Jnum | J:50232 |
| Mgi Id | MGI:1290088 | Doi | 10.4049/jimmunol.161.8.4066 |
| Citation | Riegert P, et al. (1998) Genomics, isoforms, expression, and phylogeny of the MHC class I-related MR1 gene. J Immunol 161(8):4066-77 |
| abstractText | A growing number of non-MHC-encoded class I-related molecules have been shown to perform diverse, yet essential, functions. These include T cell presentation of bacterially derived glycolipidic Ags by CD1, transcytosis of maternal IgG by the neonatal Fc receptor, enriched presence and plausible function within exocrine fluids of the Zn-alpha2-glycoprotein, subversion of NK cytolytic activity by the CMV UL18 gene product, and, finally, crucial involvement in iron homeostasis of the HFE gene. A recently described member of this family is the MHC class-I related (MR1) gene. The most notable feature of MR1 is undoubtedly its relatively high degree of sequence similarity to the MHC-encoded classical class I genes. The human chromosome 1q25.3 MR1 locus gives rise not only to the originally reported 1,263-bp cDNA clone encoding a putative 341-amino acid polypeptide chain, but to many additional transcripts in various tissues as well. Here we define the molecular identity of all human and murine MR1 isoforms generated through a complex scenario of alternative splicing, some encoding secretory variants lacking the Ig-like alpha3 domain. Moreover, we show ubiquitous transcription of these MR1 variants in several major cell lineages. We additionally report the complete 18,769-bp genomic structure of the MR1 locus, localize the murine orthologue to a syntenic segment of chromosome 1, and provide evidence for conservation of a single-copy MR1 gene throughout mammalian evolution. The 90% sequence identity between the human and mouse MR1 putative ligand binding domains together with the ubiquitous expression of this gene favor broad immunobiologic relevance. |
