Characterisation of the human central MHC gene, BAT1: Genomic structure and expression

The BAT1 gene (D6S81E) encodes a member of the DEAD-box family of RNA-bindi ng proteins, and lies in the central MHC, This region contains genes which affect susceptibility to immunopathological diseases. A 14-kb section of th e human MHC containing the BAT1 gene and a further 5-kb telomeric of BAT1 w as sequenced using DNA from individuals homozygous for HLA-A1, B8, DR3 and HLA-Al, B57, DR7. Analysis of our sequences and the previously reported hum an cDNA sequence showed that the expressed sequence of the 8.1 and 57.1 hap lotypes is identical with only minor substitutions in the introns. Phylogen etic analysis suggests BAT1 may be a translation initiation factor. Screeni ng of cells and tissues for BAT1 mRNA suggests an abundant member of a fami ly of proteins expressed in multiple cell types, notably macrophages and he patocytes. Expression was independent of MHC haplotype, consistent with the lack of sequence polymorphism.