title: Identification and regulatory analysis of rainbow trout tapasin and tapasin-related genes.
abstract: Tapasin (TAPBP) is a key member of MHC class Ia antigen-loading complexes, bridging the class Ia molecule to the transporter associated with antigen presentation (TAP). As part of an ongoing study of MHC genomics in rainbow trout, we have identified two rainbow trout TAPBP genes (Onmy-TAPBP.a and .b) and a similar but distinct TAPBP-related gene (Onmy-TAPBP-R) that had previously only been described in mammals. Physical and genetic mapping indicate that Onmy-TAPBP.a is on chromosome 18 in the MHC class Ia region and that Onmy-TAPBP.b resides on chromosome 14 in the MHC class Ib region. There are also at least two copies of TAPBP-R, Onmy-TAPBP-R.a and Onmy-TAPBP-R.b, located on chromosomes 2 and 3, respectively. Due to the central role of TAPBP expression during acute viral infection, we have characterized the transcriptional profile and regulatory regions for both Onmy-TAPBP and Onmy-TAPBP-R. Transcription of both genes increased during acute infection with infectious hematapoeitic necrosis virus (IHNV) in a fashion indicative of interferon-mediated regulation. Promoter-reporter assays in STE-137 cells demonstrate that the trout TAPBP and TAPBP-R promoters respond to interferon regulatory factors, Onmy-IRF1 and Onmy-IRF2. Overall, TAPBP is expressed at higher levels than TAPBP-R in naïve tissues and TAPBP transcription is more responsive to viral infection and IRF1 and 2 binding.
authors.affiliation: Molecular Medicine Program, University of Maryland Medical School, Baltimore, Maryland, USA.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Landis
authors.forename: Yniv
authors.initials: Y
authors.lastname: Palti
authors.forename: Jenefer
authors.initials: J
authors.lastname: Dekoning
authors.forename: Robert
authors.initials: R
authors.lastname: Drew
authors.forename: Ruth B
authors.initials: RB
authors.lastname: Phillips
authors.forename: John D
authors.initials: JD
authors.lastname: Hansen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation / Q000235:genetics; D017920:Antiporters / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002478:Cells, Cultured; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial; D017124:Conserved Sequence; D007136:Immunoglobulins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D029142:Infectious hematopoietic necrosis virus / Q000276:immunology*; D050856:Interferon Regulatory Factor-1 / Q000235:genetics*; D050836:Interferon Regulatory Factor-2 / Q000235:genetics*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D050436:Regulatory Elements, Transcriptional; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D017920:Antiporters; D007136:Immunoglobulins; D050856:Interferon Regulatory Factor-1; D050836:Interferon Regulatory Factor-2; D026901:Membrane Transport Proteins; C107762:tapasin