Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/30/2005
Publication Date: 1/15/2006
Citation: Landis, E.D., Palti, Y., Dekoning, J., Phillips, R.B., Hansen, J.D. 2006. Mapping and functional genomics of the TAPBP and TAPBP-R genes in rainbow trout. Plant and Animal Genome Conference. Meeting book of Abstracts p. 253. Interpretive Summary:
Technical Abstract: Tapasin (TAPBP) is the “keystone”of MHC class Ia antigen loading complexes, bridging the class Ia molecule to the transporter associated with antigen presentation. 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 indicates that Onmy-TAPBP.a resides on chromosome 18 in the MHC class Ia region and that Onmy-TAPBP.b is 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. Owing to the central role of TAPBP 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 was induced during infection with infectious hematapoeitic necrosis virus (IHNV)in a manner indicative of interferon-mediated regulation. Promoter-reporter assays in STE-137 cells demonstrate that the trout TAPBP and TAPBP-R promoters respond to trout interferon regulatory factors (IRF) 1 and 2. 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.