Résumé
Although present in many copies in the mouse genome, xenotropic
murine leukemia viruses cannot infect cells from laboratory mice
because of the lack of a functional cell surface receptor required for
virus entry. In contrast, cells from many nonmurine species, including
human cells, are fully permissive. Using an expression library
approach, we isolated a cDNA from HeLa cell RNA that conferred
susceptibility to xenotropic envelope protein binding and virus
infection when expressed in nonpermissive cells. The deduced product is
a 696-aa multiple-membrane spanning molecule, is widely expressed in
human tissues, and shares homology with nematode, fly, and plant
proteins of unknown function as well as with the yeast SYG1 protein,
which has been shown to interact with a G protein. This molecule also
acts as a receptor for polytropic murine leukemia viruses, consistent
with observed interference between xenotropic and polytropic viruses in
some cell types. This xenotropic and polytropic retrovirus receptor
(XPR1) is the fourth identified molecule having multiple membrane
spanning domains among mammalian type C oncoretrovirus receptors and
may play a role in G protein-coupled signal transduction, as do the
chemokine receptors required for HIV entry.