Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 292, Issue 27, Pages 11165-11177Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M117.777045
Keywords
-
Categories
Funding
- National Institutes of Health [RO1AI088001]
- University of Wisconsin-Milwaukee Research Growth Innitiative [101X333]
- National Science Foundation Major Research Instrumentation Program Grant [PHY-1126386]
Ask authors/readers for more resources
Human cells detect RNA viruses through a set of helicases called RIG-I-like receptors (RLRs) that initiate the interferon response via a mitochondrial signaling complex. Many RNA viruses also encode helicases, which are sometimes covalently linked to proteases that cleave signaling proteins. One unresolved question is how RLRs interact with each other and with viral proteins in cells. This study examined the interactions among the hepatitis C virus (HCV) helicase and RLR helicases in live cells with quantitative microspectroscopic imaging (Q-MSI), a technique that determines FRET efficiency and subcellular donor and acceptor concentrations. HEK293T cells were transfected with various vector combinations to express cyan fluorescent protein (CFP) or YFP fused to either biologically active HCV helicase or one RLR (i. e. RIG-I, MDA5, or LGP2), expressed in the presence or absence of polyinosinicpolycytidylic acid (poly(I: C)), which elicits RLR accumulation at mitochondria. Q-MSI confirmed previously reported RLR interactions and revealed an interaction between HCV helicase and LGP2. Mitochondria in CFP-RIG-I: YFP-RIG-I cells, CFPMDA5: YFP-MDA5 cells, and CFP-MDA5: YFP-LGP2 cells had higher FRET efficiencies in the presence of poly(I: C), indicating that RNA causes these proteins to accumulate at mitochondria in higher-order complexes than those formed in the absence of poly(I: C). However, mitochondria in CFP-LGP2: YFP-LGP2 cells had lower FRET signal in the presence of poly(I: C), suggesting that LGP2 oligomers disperse so that LGP2 can bind MDA5. Data support a new model where an LGP2-MDA5 oligomer shuttles NS3 to the mitochondria to block antiviral signaling.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available