title: A family of MHC class I-like genes located in the vicinity of the mouse leukocyte receptor complex.
abstract: Some members of the major histocompatibility complex (MHC) class I gene family are encoded outside the MHC. Here we describe a family of mouse class I-like genes mapping to the vicinity of the leukocyte receptor complex (LRC) on chromosome 7. This family, which we call Mill (MHC class I-like located near the LRC), has two members designated Mill1 and Mill2. Both genes are predicted to encode membrane glycoproteins with domain organization essentially similar to that of MHC class I heavy chains. The following features of Mill are noteworthy. (i) The deduced MILL proteins lack most of the residues known to be involved in the docking of peptides in classical MHC class I molecules. (ii) Among the known members of the class I gene family, MILL1 and MILL2 are related most closely to MICA/MICB encoded in the human MHC. (iii) Unlike all other known members of the class I gene family, Mill1 and Mill2 have an exon between those coding for the signal peptide and the alpha1 domain. (iv) Mill1 has a more restricted expression profile than Mill2. (v) The gene orthologous to Mill1 or Mill2 apparently is absent in the human. (vi) Mill1 and Mill2 show a limited degree of polymorphism in laboratory mice. The observation that the Mill family is related most closely to the MIC family, together with its apparent absence in the human, suggests its involvement in innate immunity.
authors.affiliation: Department of Biosystems Science, School of Advanced Sciences, Graduate University for Advanced Studies (Sokendai), Shonan Village, Hayama 240-0193, Japan. kasahara@soken.ac.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Kasahara
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Motoko
authors.initials: M
authors.lastname: Sumasu
authors.forename: Taeko
authors.initials: T
authors.lastname: Nagata
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D005805:Genes, MHC Class I; D015395:Histocompatibility Antigens Class I / Q000737:chemistry / Q000235:genetics; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D011110:Polymorphism, Genetic; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D018076:DNA, Complementary; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A; C098080:MICB antigen; D008562:Membrane Glycoproteins