Insulin signaling regulates longevity through protein phosphorylation in Caenorhabditis elegans

Nat Commun. 2021 Jul 27;12(1):4568. doi: 10.1038/s41467-021-24816-z.


Insulin/IGF-1 Signaling (IIS) is known to constrain longevity by inhibiting the transcription factor FOXO. How phosphorylation mediated by IIS kinases regulates lifespan beyond FOXO remains unclear. Here, we profile IIS-dependent phosphorylation changes in a large-scale quantitative phosphoproteomic analysis of wild-type and three IIS mutant Caenorhabditis elegans strains. We quantify more than 15,000 phosphosites and find that 476 of these are differentially phosphorylated in the long-lived daf-2/insulin receptor mutant. We develop a machine learning-based method to prioritize 25 potential lifespan-related phosphosites. We perform validations to show that AKT-1 pT492 inhibits DAF-16/FOXO and compensates the loss of daf-2 function, that EIF-2α pS49 potently inhibits protein synthesis and daf-2 longevity, and that reduced phosphorylation of multiple germline proteins apparently transmits reduced DAF-2 signaling to the soma. In addition, an analysis of kinases with enriched substrates detects that casein kinase 2 (CK2) subunits negatively regulate lifespan. Our study reveals detailed functional insights into longevity.

Publication types

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

MeSH terms

  • Algorithms
  • Amino Acid Sequence
  • Animals
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / chemistry
  • Caenorhabditis elegans Proteins / metabolism
  • Germ Cells / metabolism
  • Humans
  • Insulin / metabolism*
  • Insulin-Like Growth Factor I / metabolism
  • Longevity / physiology*
  • Models, Biological
  • Mutation / genetics
  • Phosphoproteins / metabolism
  • Phosphorylation
  • Proteome / metabolism
  • Proteomics
  • Signal Transduction*


  • Caenorhabditis elegans Proteins
  • Insulin
  • Phosphoproteins
  • Proteome
  • Insulin-Like Growth Factor I