HIV-1 enhances mTORC1 activity and repositions lysosomes to the periphery by co-opting Rag GTPases

Sci Rep. 2017 Jul 14;7(1):5515. doi: 10.1038/s41598-017-05410-0.

Abstract

HIV-1 co-opts several host machinery to generate a permissive environment for viral replication and transmission. In this work we reveal how HIV-1 impacts the host translation and intracellular vesicular trafficking machineries for protein synthesis and to impede the physiological late endosome/lysosome (LEL) trafficking in stressful conditions. First, HIV-1 enhances the activity of the master regulator of protein synthesis, the mammalian target of rapamycin (mTOR). Second, the virus commandeers mTOR-associated late endosome/lysosome (LEL) trafficking and counteracts metabolic and environmental stress-induced intracellular repositioning of LEL. We then show that the small Rag GTPases, RagA and RagB, are required for the HIV-1-mediated LEL repositioning that is likely mediated by interactions between the Rags and the viral proteins, Gag and Vif. siRNA-mediated depletion of RagA and RagB leads to a loss in mTOR association to LEL and to a blockade of viral particle assembly and release at the plasma membrane with a marked concomitant reduction in virus production. These results show that HIV-1 co-opts fundamental mechanisms that regulate LEL motility and positioning and support the notion that LEL positioning is critical for HIV-1 replication.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • HIV-1 / physiology*
  • HeLa Cells
  • Humans
  • Lysosomes / metabolism*
  • Mechanistic Target of Rapamycin Complex 1 / metabolism
  • Monomeric GTP-Binding Proteins / genetics
  • Monomeric GTP-Binding Proteins / metabolism*
  • RNA, Small Interfering / pharmacology
  • THP-1 Cells
  • TOR Serine-Threonine Kinases / metabolism*
  • Virus Assembly
  • gag Gene Products, Human Immunodeficiency Virus / metabolism
  • vif Gene Products, Human Immunodeficiency Virus / metabolism

Substances

  • RNA, Small Interfering
  • gag Gene Products, Human Immunodeficiency Virus
  • vif Gene Products, Human Immunodeficiency Virus
  • vif protein, Human immunodeficiency virus 1
  • MTOR protein, human
  • Mechanistic Target of Rapamycin Complex 1
  • TOR Serine-Threonine Kinases
  • RRAGA protein, human
  • Monomeric GTP-Binding Proteins