Somatic cell mapping of the bovine interferon-alpha receptor

The bovine interferon-alpha receptor (BoIFN-alpha R) mediates the activity of bovine IFN-alpha s and IFN-beta. In addition, human IFN-alpha s have uniformly high biological activity on bovine cells. A 32P-labeled derivative of human recombinant IFN-alpha A (HuIFN-alpha A-P1) binds well and can form a characteristic 130-kDa complex on bovine cells, but not on hamster cells. We have, therefore, analyzed the binding and covalent crosslinking of [32P]HuIFN-alpha A-P1 to a panel of bovine-hamster somatic cell hybrids. Binding to several bovine-hamster hybrid cell lines was strong (about 30-50% of that seen with bovine MDBK cells) and specific. The binding correlated uniquely with bovine syntenic group U10. In several of the hybrid lines, the ability of human IFN-alpha B to enhance the expression of endogenous MHC class I molecules correlated with the binding results. We thus conclude that the bovine IFN-alpha R structural gene (locus designation IFNAR) localizes to syntenic group U10. This group includes a number of other genes whose homologs map to human Chromosome (Chr) 21.