1. Biochemistry and Chemical Biology
  2. Immunology and Inflammation
Download icon

Establishing the role of ATP for the function of the RIG-I innate immune sensor

  1. David C Rawling
  2. Megan E Fitzgerald
  3. Anna Marie Pyle  Is a corresponding author
  1. Yale University, United States
  2. Howard Hughes Medical Institute, Yale University, United States
Research Article
  • Cited 34
  • Views 2,773
  • Annotations
Cite this article as: eLife 2015;4:e09391 doi: 10.7554/eLife.09391

Abstract

Retinoic acid-inducible gene I (RIG-I) initiates a rapid innate immune response upon detection and binding to viral RNA. This signal activation occurs only when pathogenic RNA is identified, despite the ability of RIG-I to bind endogenous RNA while surveying the cytoplasm. Here we show that ATP binding and hydrolysis by RIG-I play a key role in the identification of viral targets and the activation of signaling. Using biochemical and cell-based assays together with mutagenesis, we show that ATP binding, and not hydrolysis, is required for RIG-I signaling on viral RNA. However, we show that ATP hydrolysis does provide an important function by recycling RIG-I and promoting its dissociation from non-pathogenic RNA. This activity provides a valuable proof-reading mechanism that enhances specificity and prevents an antiviral response upon encounter with host RNA molecules.

Article and author information

Author details

  1. David C Rawling

    Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Megan E Fitzgerald

    Department of Molecular, Cellular and Developmental Biology, Howard Hughes Medical Institute, Yale University, New Haven, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Anna Marie Pyle

    Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, United States
    For correspondence
    anna.pyle@yale.edu
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Stephen C Kowalczykowski, University of California, Davis, United States

Publication history

  1. Received: June 12, 2015
  2. Accepted: September 14, 2015
  3. Accepted Manuscript published: September 15, 2015 (version 1)
  4. Version of Record published: October 27, 2015 (version 2)

Copyright

© 2015, Rawling et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 2,773
    Page views
  • 676
    Downloads
  • 34
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Download citations (links to download the citations from this article in formats compatible with various reference manager tools)

Open citations (links to open the citations from this article in various online reference manager services)

Further reading

    1. Biochemistry and Chemical Biology
    2. Cell Biology
    Mikel Garcia-Marcos
    Research Article Updated

    It has become evident that activation of heterotrimeric G-proteins by cytoplasmic proteins that are not G-protein-coupled receptors (GPCRs) plays a role in physiology and disease. Despite sharing the same biochemical guanine nucleotide exchange factor (GEF) activity as GPCRs in vitro, the mechanisms by which these cytoplasmic proteins trigger G-protein-dependent signaling in cells have not been elucidated. Heterotrimeric G-proteins can give rise to two active signaling species, Gα-GTP and dissociated Gβγ, with different downstream effectors, but how non-receptor GEFs affect the levels of these two species in cells is not known. Here, a systematic comparison of GPCRs and three unrelated non-receptor proteins with GEF activity in vitro (GIV/Girdin, AGS1/Dexras1, and Ric-8A) revealed high divergence in their contribution to generating Gα-GTP and free Gβγ in cells directly measured with live-cell biosensors. These findings demonstrate fundamental differences in how receptor and non-receptor G-protein activators promote signaling in cells despite sharing similar biochemical activities in vitro.

    1. Biochemistry and Chemical Biology
    2. Microbiology and Infectious Disease
    Zachary F Mandell et al.
    Research Article

    NusA and NusG are transcription factors that stimulate RNA polymerase pausing in Bacillus subtilis. While NusA was known to function as an intrinsic termination factor in B. subtilis, the role of NusG in this process was unknown. To examine the individual and combinatorial roles that NusA and NusG play in intrinsic termination, Term-seq was conducted in wild type, NusA depletion, DnusG, and NusA depletion DnusG strains. We determined that NusG functions as an intrinsic termination factor that works alone and cooperatively with NusA to facilitate termination at 88% of the 1400 identified intrinsic terminators. Our results indicate that NusG stimulates a sequence-specific pause that assists in the completion of suboptimal terminator hairpins with weak terminal A-U and G-U base pairs at the bottom of the stem. Loss of NusA and NusG leads to global misregulation of gene expression and loss of NusG results in flagella and swimming motility defects.