title: Identification and characterization of a beta proteasome subunit cluster in the Japanese pufferfish (Fugu rubripes).
abstract: The low molecular mass polypeptide (LMP2, LMP7, and MECL-1) genes code for beta-type subunits of the proteasome, a multimeric complex that degrades proteins into peptides as part of the MHC class I-mediated Ag-presenting pathway. These gene products are up-regulated in response to infection by IFN-gamma and replace the corresponding constitutively expressed subunits (X, Y, and Z) during the immune response. In humans, the LMP2 and LMP7 genes both reside within the class II region of the MHC (6p21.3), while MECL-1 is located at 16q22.1. In the present study, we have identified all three IFN-gamma-regulated beta-type proteasome subunits in Fugu, which are present as a cluster within the Fugu MHC class I region. We show that in this species, LMP7, LMP2, and MECL-1 are linked. Also within this cluster is an LMP2-like subunit (which seems specific to all teleosts tested to date) and a closely linked LMP7 pseudogene, indicating that within Fugu and potentially other teleosts, there has been an additional regional duplication involving these genes.
authors.affiliation: Fugu Genomics, HGMP Resource Centre, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom. mclark@hgmp.mrc.ac.uk
authors.forename: M S
authors.initials: MS
authors.lastname: Clark
authors.forename: P
authors.initials: P
authors.lastname: Pontarotti
authors.forename: A
authors.initials: A
authors.lastname: Gilles
authors.forename: A
authors.initials: A
authors.lastname: Kelly
authors.forename: G
authors.initials: G
authors.lastname: Elgar
mesh_terms: D000818:Animals; D003360:Cosmids / Q000737:chemistry / Q000302:isolation & purification; D003546:Cysteine Endopeptidases / Q000737:chemistry* / Q000235:genetics*; D005091:Exons; D005400:Fishes, Poisonous; D005796:Genes; D006801:Humans; D007438:Introns; D008285:Major Histocompatibility Complex / Q000235:genetics; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000235:genetics*; D005810:Multigene Family; D010802:Phylogeny; D046988:Proteasome Endopeptidase Complex; D011506:Proteins / Q000737:chemistry / Q000235:genetics; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: C037662:EBV-associated membrane antigen, Epstein-Barr virus; D009097:Multienzyme Complexes; D011506:Proteins; D014763:Viral Matrix Proteins; D003546:Cysteine Endopeptidases; C098949:proteasome subunit Z; C077436:LMP7 protein; C098948:PSMB10 protein, human; D046988:Proteasome Endopeptidase Complex