FIG 2.

Specificity of SLC19A1 as the receptor for GLN. (A) Neighbor-joining phylogenetic tree without distance corrections showing the GLN receptor SLC19A1 and its similarities to other SLC proteins at the amino acid level. A closely related SLC19 family member, SLC19A2, and the other folate transporter, SLC46A1 (in boldface type), were tested for their ability to render 293T cells permissive to infection by GLN. HEMV, hortulanus endogenous murine leukemia virus; BLV, bovine leukemia virus. (B) 293T cells were transduced to express SLC19A1, SLC19A2, SLC46A1, or an empty vector (EV) control. After selection with hygromycin, the cell populations were exposed to GLN-pseudotyped viruses, and fluorescence was analyzed 72 h later by microscopy. Images are from one infection assay representative of results from 3 independent experiments. (C) Viral titers of different pseudotyped viruses on the same transduced cells were measured using flow cytometry (n = 3; the standard deviations [SD] are represented by the error bars).