title: Linkage of LMP, TAP, and RING3 with Mhc class I rather than class II genes in the zebrafish.
abstract: The LMP2 and LMP7 genes code for subunits of the proteasome, a multimeric enzymatic complex that degrades proteins into peptides. The two subunits replace corresponding constitutively expressed subunits during the immune response. Some of the peptides generated by the proteasome in the cytosol are transported by the products of the TAP1 and TAP2 genes into the lumen of the endoplasmic reticulum and are loaded onto the assembling MHC class I molecules. In mammals, the LMP2, LMP7, TAP1, and TAP2 genes reside in the class II region of the Mhc, closely linked to the RING3 gene. In the present study we identified, cloned, and sequenced the LMP, TAP2, and RING3 genes of the zebrafish, Danio rerio. We identified variants of these genes and used them in a segregation analysis of haploid embryos derived from heterozygous mothers. The analysis revealed that in zebrafish, the LMP2, LMP7, TAP12, and RING3 loci are closely linked but, in contrast to mammals, the LMP/TAP/RING3 cluster resides not in the Mhc class II but in the class I region. We also confirmed that in the zebrafish, the class I and class II regions are not linked to each other. In this species, therefore, the LMP/TAP/RING3 genes are clustered with the class I genes on a chromosome that apparently does not contain any class II genes. The linkage of LMP/TAP/RING3/class I may be the original and the LMP/TAP/RING3/class II a derived arrangement of these genes.
authors.affiliation: Max-Planck-Institut für Biologie, Abteilung Immungenetik, Tübingen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Takami
authors.forename: Z
authors.initials: Z
authors.lastname: Zaleska-Rutczynska
authors.forename: F
authors.initials: F
authors.lastname: Figueroa
authors.forename: J
authors.initials: J
authors.lastname: Klein
mesh_terms: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000595:Amino Acid Sequence; D026905:Amino Acid Transport Systems; D000818:Animals; D001483:Base Sequence; D002868:Chromosomal Proteins, Non-Histone; D003546:Cysteine Endopeptidases; D005805:Genes, MHC Class I; D005802:Genes, MHC Class II; D008040:Genetic Linkage; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D011506:Proteins / Q000235:genetics*; D051381:Rats; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors; D029867:Xenopus Proteins; D014982:Xenopus laevis; D015027:Zebrafish / Q000235:genetics* / Q000276:immunology; D029961:Zebrafish Proteins; D000092468:Bromodomain Containing Proteins
chemical_list: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D026905:Amino Acid Transport Systems; D002868:Chromosomal Proteins, Non-Histone; D003546:Cysteine Endopeptidases; D017346:Protein Serine-Threonine Kinases; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D029867:Xenopus Proteins; D029961:Zebrafish Proteins; C098415:BRD2 protein, human; D000092468:Bromodomain Containing Proteins; C490844:Brd2 protein, mouse; C073119:TAP1 protein, human; C489515:TAP2 protein, Xenopus; C429825:TAT2 protein, S cerevisiae; C486171:Tap1 protein, mouse; C486172:Tap1 protein, rat; C489516:Tap2 protein, mouse; C489514:Tap2 protein, rat; C489513:tap2t protein, zebrafish; C071313:LMP-2 protein; C071692:TAP2 protein, human; C490842:BRD2 protein, Xenopus; C490843:brd2a protein, zebrafish