1. Defects in the C. elegans acyl-CoA synthase, acs-3, and nuclear hormone receptor, nhr-25, cause sensitivity to distinct, but overlapping stresses.
- Author
-
Ward JD, Mullaney B, Schiller BJ, He LD, Petnic SE, Couillault C, Pujol N, Bernal TU, Van Gilst MR, Ashrafi K, Ewbank JJ, and Yamamoto KR
- Subjects
- Animals, Animals, Genetically Modified, Antimicrobial Cationic Peptides genetics, Caenorhabditis elegans immunology, Coenzyme A Ligases genetics, Coenzyme A Ligases metabolism, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Gene Expression Regulation, Gene Knockout Techniques, Genetic Association Studies, Longevity genetics, Mutation, Phenotype, RNA Interference, Transcription Factors genetics, Transcription Factors metabolism, Transcriptome, Caenorhabditis elegans genetics, Caenorhabditis elegans metabolism, Coenzyme A Ligases deficiency, DNA-Binding Proteins deficiency, Stress, Physiological, Transcription Factors deficiency
- Abstract
Metazoan transcription factors control distinct networks of genes in specific tissues, yet understanding how these networks are integrated into physiology, development, and homeostasis remains challenging. Inactivation of the nuclear hormone receptor nhr-25 ameliorates developmental and metabolic phenotypes associated with loss of function of an acyl-CoA synthetase gene, acs-3. ACS-3 activity prevents aberrantly high NHR-25 activity. Here, we investigated this relationship further by examining gene expression patterns following acs-3 and nhr-25 inactivation. Unexpectedly, we found that the acs-3 mutation or nhr-25 RNAi resulted in similar transcriptomes with enrichment in innate immunity and stress response gene expression. Mutants of either gene exhibited distinct sensitivities to pathogens and environmental stresses. Only nhr-25 was required for wild-type levels of resistance to the bacterial pathogen P. aeruginosa and only acs-3 was required for wild-type levels of resistance to osmotic stress and the oxidative stress generator, juglone. Inactivation of either acs-3 or nhr-25 compromised lifespan and resistance to the fungal pathogen D. coniospora. Double mutants exhibited more severe defects in the lifespan and P. aeruginosa assays, but were similar to the single mutants in other assays. Finally, acs-3 mutants displayed defects in their epidermal surface barrier, potentially accounting for the observed sensitivities. Together, these data indicate that inactivation of either acs-3 or nhr-25 causes stress sensitivity and increased expression of innate immunity/stress genes, most likely by different mechanisms. Elevated expression of these immune/stress genes appears to abrogate the transcriptional signatures relevant to metabolism and development.
- Published
- 2014
- Full Text
- View/download PDF