Virus-induced double-membrane vesicles

Abstract

Many viruses that replicate in the cytoplasm compartmentalize their genome replication and transcription in specific subcellular microenvironments or organelle-like structures, to increase replication efficiency and protect against host cell defences. Recent studies have investigated the complex membrane rearrangements induced by diverse positive-strand RNA viruses, which are of two morphotypes : membrane invagination towards the lumen of the endoplasmic reticulum (ER) or other specifically targeted organelles and double-membrane vesicles (DMVs) formed by extrusion of the ER membrane. DMVs resemble small autophagosomes and the viruses inducing these intriguing organelles are known to promote autophagy, suggesting a potential link between DMVs and the autophagic pathway. In this review, we summarize recent findings concerning the biogenesis, architecture and role of DMVs in the life cycle of viruses from different families and discuss their possible connection to autophagy or other related pathways.

Figure 1

Membrane rearrangements encountered in HCV‐infected cells. A. At low magnification, a typical HCV‐infected cell shows a perinuclear cluster (dotted line) of single‐membrane vesicles (ViCs, for vesicles in cluster) surrounded by an area containing numerous DMVs. B and C. High magnification of DMVs. Careful examination of these structures shows that their thick membrane actually consist of two or more closely apposed membranes as a double membrane can be discerned in some areas (black arrows). n, nucleus.