Related Experiment Video

Updated: Jul 11, 2026

Automated Separation of C. elegans Variably Colonized by a Bacterial Pathogen
11:18

Automated Separation of C. elegans Variably Colonized by a Bacterial Pathogen

Published on: March 21, 2014

8.0K

Ubiquitin-mediated response to microsporidia and virus infection in C. elegans

Malina A Bakowski1, Christopher A Desjardins2, Margery G Smelkinson1

  • 1Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America.

Plos Pathogens
|June 20, 2014
PubMed

Insights

The ubiquitin system is crucial for C. elegans defense against microsporidia and viruses. This host response targets pathogen cells for destruction, highlighting a key immune mechanism against intracellular infections.

Area of Science:

  • Cellular and Molecular Biology
  • Parasitology
  • Immunology

Background:

  • Microsporidia are obligate intracellular pathogens infecting diverse animals, yet host responses remain poorly understood.
  • The nematode C. elegans serves as a model organism for studying host-pathogen interactions.
  • Ubiquitin-mediated pathways are vital for cellular protein regulation and immune responses.

Purpose of the Study:

  • To investigate the in vivo role of the ubiquitin system in host defense against microsporidian (Nematocida parisii) and viral infections in C. elegans.
  • To elucidate the specific components and mechanisms of the ubiquitin-mediated immune response.
  • To compare the host response to microsporidia and viral pathogens.

Main Methods:

  • Gene expression analysis in C. elegans upon infection.
  • Functional studies of ubiquitin ligase components, including cul-6.
  • Assessment of pathogen targeting via ubiquitylation.
  • Investigation of the proteasome and autophagy pathways in host defense.
  • Pharmacological inhibition of microsporidia and the ubiquitin-proteasome system (UPS).

Main Results:

  • Host gene expression response to N. parisii resembles that of viral infection.
  • SCF ubiquitin ligase components, like cul-6, are upregulated and essential for targeting N. parisii.
  • Ubiquitylation, the proteasome, and autophagy are critical for defense against N. parisii.
  • SCF ligase components play a more significant role in antiviral defense than anti-microsporidian defense.
  • N. parisii may suppress the host ubiquitylation system; its inhibition enhances host targeting.
  • Perturbation of the UPS triggers a transcriptional response to infection.

Conclusions:

  • The ubiquitin system is a critical component of C. elegans innate immunity against both microsporidian and viral intracellular pathogens.
  • Ubiquitin-mediated defense mechanisms, involving SCF ligases, proteasomes, and autophagy, are conserved and essential for controlling pathogen load.
  • Nematocida parisii actively interferes with host ubiquitylation, suggesting a co-evolutionary arms race.
  • The ubiquitin-proteasome system serves as a key sensor for intracellular pathogen invasion, initiating a transcriptional defense program.

More Related Videos

Studying Inherited Immunity in a Caenorhabditis elegans Model of Microsporidia Infection09:24

Studying Inherited Immunity in a Caenorhabditis elegans Model of Microsporidia Infection

Published on: April 6, 2022

2.0K
RNA Fluorescence in situ Hybridization FISH to Visualize Microbial Colonization and Infection in Caenorhabditis elegans Intestines08:58

RNA Fluorescence in situ Hybridization FISH to Visualize Microbial Colonization and Infection in Caenorhabditis elegans Intestines

Published on: July 27, 2022

4.6K

Related Concept Videos

Intralumenal Vesicles and Multivesicular Bodies01:38

Intralumenal Vesicles and Multivesicular Bodies

Intraluminal vesicles (ILVs) are small vesicles 50-80 nm in diameter formed during the maturation of early endosomes. A specialized endosome containing numerous ILVs is called a multivesicular body (MVB). ILVs contain internalized molecules such as antigens, nucleic acids, proteins, and metabolites. Some of these molecules are released from the MVBs inside exosomes and are transported to other cells. Other MVBs contain molecules that are retained in the ILVs and are later degraded within the...
The Unfolded Protein Response01:37

The Unfolded Protein Response

The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...
Regulation of the Unfolded Protein Response01:31

Regulation of the Unfolded Protein Response

Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
Fungal Phylum Microsporidia01:28

Fungal Phylum Microsporidia

Microsporidia are a group of obligate intracellular fungi that were initially classified as protists but were later reclassified based on phylogenetic, molecular, and structural evidence linking them to the Chytridiomycota. These unicellular, non-motile organisms are highly specialized parasites that infect a wide range of animal hosts, including humans. They have evolved extensive genomic and metabolic reductions, making them highly dependent on their hosts for survival.Morphology and Genomic...