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More On PHA-4, Calorie Restriction and Longevity
(Wednesday May 02 2007)
 | A better article on the latest calorie restriction gene via EurekAlert!: "After 72 years of not knowing how calorie restriction works, we finally have genetic evidence to unravel the underlying molecular program required for increased longevity in response to calorie restriction ... Loss of only one of the genes, a gene encoding the protein PHA-4, negated the lifespan-enhancing effect of calorie restriction in worms. And, when researchers undertook the opposite experiment - by overexpressing pha-4 in worms - the longevity effect was enhanced. ... So far, only one other gene, called sir-2, has been implicated in the life- and health-prolonging response to calorie restriction. Increased amounts of SIR-2 protein extend longevity of yeast, worms, and flies, but while loss of sir-2 disrupts the calorie restriction response only in yeast, it has no effect on other organisms, such as worms. ... We know three distinct pathways that affect longevity: insulin/IGF signaling, calorie restriction, and the mitochondrial electron transport chain pathway, yet it is still not clear where sir-2 fits in. It seems to meddle with more than one pathway. PHA-4 is specific for calorie restriction as it does not affect the other pathways." |
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