New lifespan extension genes found

September 29, 2005

New genes tied to lifespan extension in yeast have been identified by researchers from UC Davis and Harvard Medical School.

Drastically reducing calorie intake, or caloric restriction, is known to extend the lifespan of species including yeast, worms and rodents. Previous research linked a gene called Sir2 with lifespan extension due to caloric restriction, but worms and yeast that lack Sir2 also live longer when put on a tough diet, showing that some other genes must be at work.

Researchers led by David Sinclair at Harvard Medical School and Su-Ju Lin at UC Davis' Center for Genetics and Development and Section of Microbiology screened for other life-extending genes in yeast. They found a gene called Hst2 that accounts for most of the difference.

Deleting Hst2 and Sir2 blocked most of the beneficial effect of caloric restriction. When Hst2 was overexpressed, so that the gene was more active than normal, the yeast lived longer than normal. A third gene, Hst1, appears to act when both Sir2 and Hst2 are missing.

Sir2 and the newly identified Hst genes account for all of the life-prolonging effects of caloric restriction in yeast, Lin said.

In yeast, the effects of aging seem to be due to a build-up of toxic circular DNA molecules that accidentally get copied out of ribosomal DNA, an unstable area of the yeast genome that contains hundreds of repeated sequences.

The researchers showed that caloric restriction drastically reduces recombination of ribosomal DNA, and that deleting Hst2 and Sir2 blocks this effect.

Very similar genes are found in widely different animals including worms, flies and rodents. But the targets of these genes are likely to be different, as the toxic DNA circles have not been identified in more advanced organisms, Lin said.

The work was published in the Sept. 16 issue of Science.
-end-


University of California - Davis

Related Aging Articles from Brightsurf:

Surprises in 'active' aging
Aging is a process that affects not only living beings.

Aging-US: 'From Causes of Aging to Death from COVID-19' by Mikhail V. Blagosklonny
Aging-US recently published ''From Causes of Aging to Death from COVID-19'' by Blagosklonny et al. which reported that COVID-19 is not deadly early in life, but mortality increases exponentially with age - which is the strongest predictor of mortality.

Understanding the effect of aging on the genome
EPFL scientists have measured the molecular footprint that aging leaves on various mouse and human tissues.

Muscle aging: Stronger for longer
With life expectancy increasing, age-related diseases are also on the rise, including sarcopenia, the loss of muscle mass due to aging.

Aging memories may not be 'worse, 'just 'different'
A study from the Department of Psychological & Brain Sciences in Arts & Sciences adds nuance to the idea that an aging memory is a poor one and finds a potential correlation between the way people process the boundaries of events and episodic memory.

A new biomarker for the aging brain
Researchers at the RIKEN Center for Biosystems Dynamics Research (BDR) in Japan have identified changes in the aging brain related to blood circulation.

Scientists invented an aging vaccine
A new way to prevent autoimmune diseases associated with aging like atherosclerosis, Alzheimer's disease, and Parkinson's disease was described in the article.

The first roadmap for ovarian aging
Infertility likely stems from age-related decline of the ovaries, but the molecular mechanisms that lead to this decline have been unclear.

Researchers discover new cause of cell aging
New research from the USC Viterbi School of Engineering could be key to our understanding of how the aging process works.

Deep Aging Clocks: The emergence of AI-based biomarkers of aging and longevity
The advent of deep biomarkers of aging, longevity and mortality presents a range of non-obvious applications.

Read More: Aging News and Aging Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.