A nematode-derived, mitochondrial stress signaling-regulated peptide exhibits broad antibacterial activity

Biol Open. 2021 May 15;10(5):bio058613. doi: 10.1242/bio.058613. Epub 2021 May 20.


A dramatic rise of infections with antibiotic-resistant bacterial pathogens continues to challenge the healthcare field due to the lack of effective treatment regimes. As such, there is an urgent need to develop new antimicrobial agents that can combat these multidrug-resistant superbugs. Mitochondria are central regulators of metabolism and other cellular functions, including the regulation of innate immunity pathways involved in the defense against infection. The mitochondrial unfolded protein response (UPRmt) is a stress-activated pathway that mitigates mitochondrial dysfunction through the regulation of genes that promote recovery of the organelle. In the model organism Caenorhabditis elegans, the UPRmt also mediates an antibacterial defense program that combats pathogen infection, which promotes host survival. We sought to identify and characterize antimicrobial effectors that are regulated during the UPRmt. From our search, we discovered that the antimicrobial peptide CNC-4 is upregulated during this stress response. CNC-4 belongs to the caenacin family of antimicrobial peptides, which are predominantly found in nematodes and are known to have anti-fungal properties. Here, we find that CNC-4 also possesses potent antimicrobial activity against a spectrum of bacterial species and report on its characterization.

Keywords: Antimicrobial peptide; CNC-4; Caenacins; Innate immunity; Mitochondria; Mitochondrial UPR; Stress response.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antimicrobial Peptides / chemistry
  • Antimicrobial Peptides / metabolism*
  • Antimicrobial Peptides / pharmacology*
  • Bacteria / drug effects*
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / immunology
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism
  • Caenorhabditis elegans Proteins / pharmacology
  • Cell Line
  • Cell Membrane Permeability / drug effects
  • Cell Survival / drug effects
  • Immunity, Innate
  • Mitochondria / genetics*
  • Mitochondria / metabolism*
  • Signal Transduction*
  • Stress, Physiological*
  • Unfolded Protein Response


  • Antimicrobial Peptides
  • Caenorhabditis elegans Proteins