Lipid metabolism is involved in the association of rotavirus viroplasms with endoplasmic reticulum membranes

Abstract

Rotavirus (RV) replication occurs in cytoplasmic membrane-less, electron-dense inclusions termed viroplasms, composed of viral and cellular elements. These inclusions have been shown to colocalize with components of the lipid droplets (LDs), unique organelles that play an essential role in lipid metabolism. Given the robust LDs-viroplasm association, LDs have been proposed to serve as a scaffold for viroplasm assembly. Interestingly, no evidence has described the participation of lipid metabolism in other RV replication steps. Here, we report that lipid metabolism is essential to maintain the production of the infectious virus through a process independent of viroplasm biogenesis. Disruption of the lipogenesis-lipolysis balance dissociates endoplasmic reticulum membranes from viroplasms, suggesting that lipid metabolism is essential for a continuous flux of lipids to allow the association between viroplasms and ER membranes. LDs could also be relevant as lipid reservoirs for membrane synthesis required to form mature infectious rotavirus particles.

Keywords: Lipid droplets; Lipogenesis; Lipolysis; Rotavirus; Viroplasms.