Inhibition of RIG-I and MDA5-dependent antiviral response by gC1qR at mitochondria

Proc Natl Acad Sci U S A. 2009 Feb 3;106(5):1530-5. doi: 10.1073/pnas.0811029106. Epub 2009 Jan 21.

Abstract

gC1qR is one of the C1q receptors implicated in the regulation of innate and adaptive immunity. We found that gC1qR inhibits RIG-I and MDA5-dependent antiviral signaling. Double stranded RNA and virus trigger the translocation of gC1qR to the mitochondrial outer membrane leading to the interaction of gC1qR with the RIG-I and MDA5 adaptor, VISA/MAVS/IPS-1/Cardif. The interaction of gC1qR with VISA/MAVS/IPS-1/Cardif at mitochondria results in the disruption of RIG-I and MDA5 signaling and the promotion of virus replication. Knockdown of endogenous gC1qR enhances RIG-I-dependent antiviral signaling, and augments the inhibition of virus proliferation. Therefore, gC1qR is a physiological inhibitor of the RIG-I and MDA5-mediated antiviral signaling pathway. These data uncover a new viral mechanism used to negatively control antiviral signaling in host cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier Proteins / metabolism
  • Carrier Proteins / physiology*
  • Cell Line
  • DEAD Box Protein 58
  • DEAD-box RNA Helicases / antagonists & inhibitors*
  • DEAD-box RNA Helicases / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • Gene Knockdown Techniques
  • Humans
  • Immunity, Innate
  • Interferon-Induced Helicase, IFIH1
  • Mitochondria / metabolism*
  • Mitochondrial Proteins / metabolism
  • Mitochondrial Proteins / physiology*
  • Protein Transport
  • Receptors, Immunologic
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction
  • Virus Diseases / immunology*
  • Virus Diseases / metabolism

Substances

  • C1QBP protein, human
  • Carrier Proteins
  • Mitochondrial Proteins
  • Receptors, Immunologic
  • RIGI protein, human
  • IFIH1 protein, human
  • DEAD Box Protein 58
  • DEAD-box RNA Helicases
  • Interferon-Induced Helicase, IFIH1