LC-MS proteomics analysis of the insulin/IGF-1-deficient Caenorhabditis elegans daf-2(e1370) mutant reveals extensive restructuring of intermediary metabolism

J Proteome Res. 2014 Apr 4;13(4):1938-56. doi: 10.1021/pr401081b. Epub 2014 Mar 3.

Abstract

The insulin/IGF-1 receptor is a major known determinant of dauer formation, stress resistance, longevity, and metabolism in Caenorhabditis elegans. In the past, whole-genome transcript profiling was used extensively to study differential gene expression in response to reduced insulin/IGF-1 signaling, including the expression levels of metabolism-associated genes. Taking advantage of the recent developments in quantitative liquid chromatography mass spectrometry (LC-MS)-based proteomics, we profiled the proteomic changes that occur in response to activation of the DAF-16 transcription factor in the germline-less glp-4(bn2);daf-2(e1370) receptor mutant. Strikingly, the daf-2 profile suggests extensive reorganization of intermediary metabolism, characterized by the upregulation of many core intermediary metabolic pathways. These include glycolysis/gluconeogenesis, glycogenesis, pentose phosphate cycle, citric acid cycle, glyoxylate shunt, fatty acid β-oxidation, one-carbon metabolism, propionate and tyrosine catabolism, and complexes I, II, III, and V of the electron transport chain. Interestingly, we found simultaneous activation of reciprocally regulated metabolic pathways, which is indicative of spatiotemporal coordination of energy metabolism and/or extensive post-translational regulation of these enzymes. This restructuring of daf-2 metabolism is reminiscent to that of hypometabolic dauers, allowing the efficient and economical utilization of internal nutrient reserves and possibly also shunting metabolites through alternative energy-generating pathways to sustain longevity.

Publication types

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

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / analysis
  • Caenorhabditis elegans Proteins / chemistry
  • Caenorhabditis elegans Proteins / genetics*
  • Caenorhabditis elegans Proteins / metabolism
  • Forkhead Transcription Factors
  • Gene Knockdown Techniques
  • Insulin / genetics*
  • Insulin-Like Growth Factor I / genetics*
  • Metabolic Networks and Pathways / genetics
  • Mutation / genetics
  • Proteome / analysis
  • Proteome / chemistry
  • Proteome / genetics*
  • Proteome / metabolism
  • Proteomics / methods
  • Receptor, Insulin / genetics*
  • Transcription Factors / analysis
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Caenorhabditis elegans Proteins
  • Forkhead Transcription Factors
  • Insulin
  • Proteome
  • Transcription Factors
  • daf-16 protein, C elegans
  • Insulin-Like Growth Factor I
  • DAF-2 protein, C elegans
  • Receptor, Insulin