COMPARISON OF CDNAS ENCODING THE GIBBON APE LEUKEMIA-VIRUS RECEPTOR FROM SUSCEPTIBLE AND NON-SUSCEPTIBLE MURINE CELLS

The gibbon ape leukaemia virus (GaLV) family of type C retroviruses co nsists of five closely related viral isolates, GaLV SF, GaLV SEATO, Ga LV Br, GaLV H and simian sarcoma-associated virus. The cDNA encoding t he human receptor for GaLV SEATO had previously been isolated. We now demonstrate that all of the above GaLVs can use the human form of the GaLV receptor to infect cells. All murine cells analysed to date have been found to be resistant to infection by GaLVs owing to the absence of a functional GaLV receptor. We have now identified a murine cell li ne which is unique in its susceptibility to GaLV infection. This cell line was established from a Japanese feral mouse, Mus musculus molossi nus. We cloned and sequenced the cDNA for the receptor expressed in th ese cells and compared it to the cDNA for the GaLV receptor expressed in resistant murine cells such as NIH 3T3 (derived from M m. musculus) and MDTF (derived from M. dunni tail fibroblasts). The crucial region for GaLV infection (the fourth extracellular domain) from the functio nal M. m. molossinus GaLV receptor is quite divergent from the same re gion of the M. m. musculus and M. dunni proteins, but similar to that of the functional human GaLV receptor. These results confirm the impor tance of the amino acids of this region in GaLV receptor function.