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Analysis of Group IV Viral SSHHPS Using In Vitro and In Silico Methods
10:40

Analysis of Group IV Viral SSHHPS Using In Vitro and In Silico Methods

Published on: December 21, 2019

Dissociation of a MAVS/IPS-1/VISA/Cardif-IKKepsilon molecular complex from the mitochondrial outer membrane by

Rongtuan Lin1, Judith Lacoste, Peyman Nakhaei

  • 1Lady Davis Institute for Medical Research, McGill University, Montreal H3T 1E2, Quebec, Canada. rongtuan.lin@mcgill.ca

Journal of Virology
|May 30, 2006
PubMed

Insights

Hepatitis C virus evades the host antiviral response by cleaving the MAVS/IPS-1/VISA/Cardif protein, disrupting RIG-I signaling. This cleavage prevents the mitochondrial localization of key signaling molecules, hindering the antiviral immune response.

Area of Science:

  • Virology
  • Immunology
  • Molecular Biology

Background:

  • RIG-I detects intracellular RNA virus infection, initiating the host antiviral response.
  • MAVS/IPS-1/VISA/Cardif acts as an adapter linking RIG-I to downstream signaling.
  • Hepatitis C virus (HCV) protease NS3-4A targets MAVS for immune evasion.

Purpose of the Study:

  • To investigate the role of KIAA1271 (K1271) in the RIG-I signaling pathway.
  • To elucidate the mechanism by which HCV NS3-4A disrupts the antiviral response.
  • To identify host factors involved in HCV immune evasion.

Main Methods:

  • Python-based novel search program for protein identification.
  • Biochemical analysis.
  • Subcellular fractionation and confocal microscopy.
  • Site-directed mutagenesis.

Main Results:

  • KIAA1271 shares identity with MAVS/IPS-1/VISA/Cardif and contains a CARD-like domain.
  • NS3-4A cleavage of MAVS/IPS-1/VISA/Cardif/K1271 causes dissociation from mitochondria, disrupting antiviral signaling.
  • HCV NS3-4A disrupts the colocalization of MAVS and IKKepsilon at the mitochondrial membrane.
  • Mutation of MAVS cysteine 508 prevents NS3-4A-mediated disruption of mitochondrial localization.

Conclusions:

  • HCV NS3-4A cleaves MAVS/IPS-1/VISA/Cardif/K1271, a critical step in viral immune evasion.
  • Disruption of MAVS mitochondrial localization and IKKepsilon colocalization impairs the host interferon antiviral response.
  • Targeting MAVS cleavage is a key strategy for HCV to evade innate immunity.

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