Telomeres, the nucleolus and aging.
Reactivation of telomerase in cultured human cells extends their replicative life span beyond the Hayflick limit. How telomere shortening triggers cell senescence and whether it contributes to aging in vivo are under investigation. Studies in yeast have revealed another site critical to cellular aging: the nucleolus. The accumulation of ribosomal DNA circles is a cause of aging in this organism. The possible relevance of this mechanism to human aging is also being considered.
Johnson
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FB
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA. bjohnson@mit.edu
Marciniak
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RA
Guarente
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L
D000375:Aging / Q000235:genetics; D000818:Animals; D002466:Cell Nucleolus / Q000235:genetics*; D016922:Cellular Senescence / Q000235:genetics*; D006801:Humans; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016615:Telomere / Q000502:physiology*