Xenotropic And Polytropic Retrovirus Receptor 1 (XPR1)

Expression of XPR1 in mouse and hamster MLV-resistant fibroblasts rendered the cells susceptible to both X- and P-MLV. The deduced 696-amino acid XPR1 protein contains 8 or 9 potential membrane-spanning regions, 7 potential N-glycosylation sites, and 7 dileucines that may stimulate endocytosis via clathrin-coated pits.

Northern blot analysis detected a 4.5-kb XPR1 transcript in all tissues tested, with highest expression in pancreas, kidney, placenta, hematopoietic tissues, and heart, and lowest expression in skeletal muscle. Expression of XPR1 was greater in fetal liver than adult liver. A 9.5-kb XPR1 transcript was also detected in all tissues tested except liver and bone marrow.