Lifespan and dauer regulation by tissue-specific activities of Caenorhabditis elegans DAF-18

Dev Biol. 2005 Oct 1;286(1):91-101. doi: 10.1016/j.ydbio.2005.07.010.

Abstract

In Caenorhabditis elegans, the insulin/IGF-1 DAF-2 receptor controls entry into dauer and longevity. DAF-2 signaling cascade includes the PI3 kinase homolog AGE-1 and the FOXO transcription factor DAF-16. The DAF-2 pathway is downregulated by DAF-18 which is encoded by the ortholog of the human tumor suppressor gene PTEN. We have previously shown that, like PTEN, DAF-18 antagonizes the activity of PI3 kinase/AGE-1. To further explore the role of DAF-18 in the regulation of the insulin pathway, we investigated which tissue(s) DAF-18 functions in to regulate dauer formation and lifespan. Our data show that complete dauer formation requires daf-18 expression in several tissues and that the remodeling of dauer tissues depends on both cell autonomous and cell nonautonomous daf-18 function(s). Conversely, daf-18 expression increases adult lifespan in all individual tissues tested. Furthermore, we show that the role of DAF-18 in dauer and lifespan control depends on DAF-16 activation, which is regulated by both cell autonomous and cell nonautonomous DAF-18 function(s) and in a tissue-specific manner. Overall, our data strongly suggest that several tissues act as signaling centers to mediate DAF-18 function and that DAF-18 could act outside the canonical DAF-2/DAF-16 pathway to regulate dauer and lifespan.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / growth & development*
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / physiology*
  • Forkhead Transcription Factors
  • Gene Expression Regulation, Developmental
  • Genes, Helminth
  • Humans
  • Insulin / metabolism
  • Larva / growth & development
  • Longevity
  • Promoter Regions, Genetic
  • Receptor, Insulin / genetics
  • Receptor, Insulin / physiology
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction
  • Tissue Distribution
  • Transcription Factors / genetics
  • Transcription Factors / physiology

Substances

  • Caenorhabditis elegans Proteins
  • DAF-18 protein, C elegans
  • Forkhead Transcription Factors
  • Insulin
  • Recombinant Fusion Proteins
  • Transcription Factors
  • daf-16 protein, C elegans
  • DAF-2 protein, C elegans
  • Receptor, Insulin