Cowpea mosaic virus infection induces a massive proliferation of endoplasmic reticulum but not Golgi membranes and is dependent on de novo membrane synthesis
Je. Carette et al., Cowpea mosaic virus infection induces a massive proliferation of endoplasmic reticulum but not Golgi membranes and is dependent on de novo membrane synthesis, J VIROLOGY, 74(14), 2000, pp. 6556-6563
Replication of cowpea mosaic virus (CPMV) is associated with small membrano
us vesicles that are induced upon infection. The effect of CPMV replication
on the morphology and distribution of the endomembrane system in living pl
ant cells was studied by expressing green fluorescent protein (GFP) targete
d to the endo plasmic reticulum (ER) and the Golgi membranes. CPMV infectio
n was found to induce an extensive proliferation of the ER, whereas the dis
tribution and morphology of the Golgi stacks remained unaffected. Immunoloc
alization experiments using fluorescence confocal microscopy showed that th
e proliferated ER membranes were closely associated with the electron-dense
structures that contain the replicative proteins encoded by RNA1. Replicat
ion of CPMV was strongly inhibited by cerulenin, an inhibitor of de novo li
pid synthesis, at concentrations where the replication of the two unrelated
viruses alfalfa mosaic virus and tobacco mosaic virus was largely unaffect
ed. These results suggest that proliferating ER membranes produce the membr
anous vesicles formed during CPMV infection and that this process requires
continuous lipid biosynthesis.