Rotavirus increases levels of lipidated LC3 supporting accumulation of infectious progeny virus without inducing autophagosome formation

PLoS One. 2014 Apr 15;9(4):e95197. doi: 10.1371/journal.pone.0095197. eCollection 2014.

Abstract

Replication of many RNA viruses benefits from subversion of the autophagic pathway through many different mechanisms. Rotavirus, the main etiologic agent of pediatric gastroenteritis worldwide, has been recently described to induce accumulation of autophagosomes as a mean for targeting viral proteins to the sites of viral replication. Here we show that the viral-induced increase of the lipidated form of LC3 does not correlate with an augmented formation of autophagosomes, as detected by immunofluorescence and electron microscopy. The LC3-II accumulation was found to be dependent on active rotavirus replication through the use of antigenically intact inactivated viral particles and of siRNAs targeting viral genes that are essential for viral replication. Silencing expression of LC3 or of Atg7, a protein involved in LC3 lipidation, resulted in a significant impairment of viral titers, indicating that these elements of the autophagic pathway are required at late stages of the viral cycle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy*
  • Cell Line
  • Chlorocebus aethiops
  • Lipid Metabolism*
  • Microtubule-Associated Proteins / metabolism*
  • Phagosomes / metabolism*
  • Rotavirus / physiology*
  • Virus Replication

Substances

  • Microtubule-Associated Proteins

Grants and funding

FA was supported by a FIRB-Futuro in Ricerca grant (RBFR08HSWG, http://futuroinricerca.miur.it) funded by the Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR), Italy. GDL was supported by an ICGEB pre-doctoral fellowship. CE and EMS were supported by Canton Zurich to the University of Zurich. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.