Retroviral genomic RNAs are transported to the plasma membrane by endosomal vesicles.
The viral genomes of alpha- and gamma-retroviruses follow an outbound route through the cytoplasm before assembling with the budding particle at the plasma membrane. We show here that murine leukemia virus (MLV) RNAs are transported on lysosomes and transferrin-positive endosomes. Transport on transferrin-positive vesicles requires both Gag and Env polyproteins. In the presence of Env, Gag is rerouted from lysosomes to transferrin-positive endosomes, and virion production becomes highly sensitive to drugs poisoning vesicular and endosomal traffic. Vesicular transport of the RNA does not require prior endocytosis, indicating that it is recruited directly from the cytosol. Viral prebudding complexes containing Env, Gag, and retroviral RNAs are thus formed on endosomes, and subsequently routed to the plasma membrane. This may allow retroviruses to hijack the endosomal machinery as part of their biosynthetic pathway. More generally, tethering to vesicles may provide an efficient mechanism for directed RNA transport.
Basyuk
Eugenia
E
IGMM-CNRS UMR5535, Université Montpellier II, IFR 24, 1919, route de Mende, 34293 Cedex 5, Montpellier, France.
Galli
Thierry
T
Mougel
Marylène
M
Blanchard
Jean-Marie
JM
Sitbon
Marc
M
Bertrand
Edouard
E
D016475:3T3 Cells; D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism*; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism*; D015686:Gene Products, env / Q000378:metabolism; D015683:Gene Products, gag / Q000378:metabolism; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006801:Humans; D009052:Leukemia Virus, Murine / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D012367:RNA, Viral / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics*
D015686:Gene Products, env; D015683:Gene Products, gag; D008164:Luminescent Proteins; D012367:RNA, Viral; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins