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The interaction between FOXO and SIRT1: tipping the balance towards survival

Maria E Giannakou1, Linda Partridge

  • 1Department of Biology, University College London, London WC1E 6BT, UK.

Trends in Cell Biology
|August 17, 2004
PubMed

Insights

Overexpressing Sir2 protein deacetylase extends lifespan in yeast and worms by interacting with the FOXO transcription factor. Mammalian SIRT1 deacetylates FOXO proteins, promoting cell survival and potentially increasing longevity.

Area of Science:

  • Genetics
  • Molecular Biology
  • Aging Research

Background:

  • The NAD-dependent protein deacetylase Sir2 and the FOXO transcription factor are known to influence lifespan.
  • Sir2 overexpression extends lifespan in model organisms like yeast and Caenorhabditis elegans.
  • Lifespan extension in C. elegans by Sir2 requires the FOXO homolog, DAF-16.

Purpose of the Study:

  • To elucidate the mechanisms underlying the genetic interaction between Sir2 and FOXO homologues in lifespan regulation.
  • To investigate the role of mammalian Sir2 homologues (SIRT1) and FOXO proteins in cellular processes related to aging.

Main Methods:

  • Focus on recent articles examining mammalian homologues of Sir2 and FOXO.
  • Analysis of protein deacetylation activity.
  • Investigation of downstream cellular effects such as apoptosis and cell-cycle arrest.

Main Results:

  • Mammalian SIRT1 deacetylates FOXO3 and/or FOXO4.
  • SIRT1 activity attenuates FOXO-induced apoptosis (programmed cell death).
  • SIRT1 activity potentiates FOXO-induced cell-cycle arrest.

Conclusions:

  • SIRT1-mediated deacetylation of FOXO proteins is a key mechanism linking these factors to lifespan regulation.
  • SIRT1 may promote longevity by shifting cellular responses from death pathways towards survival pathways.
  • Understanding these interactions provides insights into conserved aging mechanisms across species.

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