Naturally Occurring Polymorphisms of the Mouse Gammaretrovirus Receptors CAT-1 and XPR1 Alter Virus Tropism and Pathogenicity
Figure 1
Predicted topology and sequence variation of the CAT-1 receptor for mouse ecotropic gammaretroviruses. (a) Putative topology identifies 14 predicted transmembrane domains. The third extracellular loop contains critical residues for receptor function (in red) and two N-linked glycosylation sites. (b) Sequence variation in the CAT-1 third extracellular loop. At the top are three sequence variants found in Mus with residues critical for entry in red. Virus infectivity of cells expressing these receptors is measured as the log10 titer of FFU/100 L of viral Env pseudotypes carrying the LacZ reporter gene; ND: not done. Consensus sites for N-glycosylation are underlined. CAT-1 sequence variation is shown for mouse CAT-1 variants mCAT-1 (NIH 3T3), dCAT-1 (M. dunni), and minCAT-1 (M. minutoides). E-MLV-infected Mus species M. castaneus, M. molossinus, M. spicilegus, and M. musculus are identical to mCAT-1 in the indicated region. Also shown are CAT-1 sequences for virus-susceptible species hamster (ha), rat (r), and XC rat cells (xc) and for virus-resistant human (hu).
