Related Experiment Video

Updated: Aug 13, 2025

Monitoring Activation of the Antiviral Pattern Recognition Receptors RIG-I And PKR By Limited Protease Digestion and Native PAGE
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New role of gramicidin A in RIG-I-like receptors-mediated IFN signalling

Xiao Li1, Xinyuan Sun1, Zhongyi Yan2

  • 1School of Pharmaceutical Science and Technology, Tianjin University and Health-Biotech United Group Joint Laboratory of Innovative Drug Development and Translational Medicine, Tianjin University, Tianjin, China.

Immunology
|January 23, 2023
PubMed

Insights

The antibiotic gramicidin A enhances melanoma differentiation-associated protein 5 (MDA5) signaling, a key part of the innate immune response. This discovery offers a new method to modulate MDA5 activity during viral infections.

Area of Science:

  • Immunology
  • Molecular Biology
  • Virology

Background:

  • Pattern recognition receptors (PRRs) detect pathogen-associated molecular patterns to activate interferon (IFN) signaling.
  • Melanoma differentiation-associated protein 5 (MDA5) senses viral double-stranded RNAs (dsRNAs) in the cytoplasm, initiating immune responses.
  • Regulation of PRR activity is crucial for controlling the strength of IFN signaling.

Purpose of the Study:

  • To identify novel small molecules that modulate MDA5 activity.
  • To investigate the mechanism by which gramicidin A affects MDA5-mediated IFN signaling.

Main Methods:

  • Virtual screening of chemical compounds using the MDA5-dsRNA complex structure (PDB: 4GL2).
  • Cytotoxic assays and IFN signaling assays to evaluate gramicidin A's effect.
  • Sucrose gradient ultracentrifugation to assess MDA5 oligomerization.

Main Results:

  • Gramicidin A was identified as a stimulator that enhances MDA5-mediated IFN signaling.
  • Gramicidin A's known membrane-disrupting activity was found to be dispensable for enhancing MDA5 signaling.
  • Gramicidin A treatment increased MDA5 oligomerization in the presence of dsRNA.

Conclusions:

  • Gramicidin A plays a novel role in innate immunity by enhancing MDA5 activity.
  • Gramicidin A serves as a valuable tool for manipulating MDA5 function in immune studies.
Keywords:
GOFIFNMAVSMDA5RIG-Igramicidin A

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