DEFINITION OF A DOMAIN OF GLVR1 WHICH IS NECESSARY FOR INFECTION BY GIBBON APE LEUKEMIA-VIRUS AND WHICH IS HIGHLY POLYMORPHIC BETWEEN SPECIES

Expression of human GLVR1 in mouse cells confers susceptibility to inf ection by gibbon ape leukemia virus (GALV), while the normally express ed mouse Glvr-1 does not. Since human and murine GLVR1 proteins differ at 64 positions in their sequences, some of the residues differing be tween the two proteins are critical for infection. To identify these, a series of hybrids and in vitro-constructed mutants were tested for t he ability to confer susceptibility- to infection. The results indicat ed that human GLVR1 residues 550 to 55 1, located in a cluster of seve n of the sites that differ between the human and mouse proteins, are t he only residues differing between the two which must be in the human protein form to allow infection. Sequencing of a portion of GLVR1 from the rat (which is infectible) confirmed the importance of this cluste r in that it contained the only notable differences between the rat an d mouse proteins. This region, which also differs substantially betwee n the rat and the human proteins, therefore exhibits a pronounced tend ency for polymorphism.