Aging and calorie restriction modulate yeast redox state, oxidized protein removal, and the ubiquitin–proteasome system

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• 作者：Fernanda Marques da Cunha^a ; Marilene Demasi^b ; ^{marimasi@butantan.gov.br"" rel=""nofollow} ; Alicia J. Kowaltowski^a ; ^{alicia@iq.usp.br"" rel=""nofollow}
• 关键词：Caloric restriction ; Life span ; Redox state ; Proteasome ; Ubiquitination ; Free radicals
• 刊名：Free Radical Biology and Medicine
• 出版年：2011
• 出版时间：1 August 2011
• 年：2011
• 卷：51
• 期：3
• 页码：664-670
• 全文大小：476 K

文摘

The ubiquitin–proteasome system governs the half-life of most cellular proteins. Calorie restriction (CR) extends the maximum life span of a variety of species and prevents oxidized protein accumulation. We studied the effects of CR on the ubiquitin–proteasome system and protein turnover in aging Saccharomyces cerevisiae. CR increased chronological life span as well as proteasome activity compared to control cells. The levels of protein carbonyls, a marker of protein oxidation, and those of polyubiquitinated proteins were modulated by CR. Controls, but not CR cells, exhibited a significant increase in oxidized proteins. In keeping with decreased proteasome activity, polyubiquitinated proteins were increased in young control cells compared to time-matched CR cells, but were profoundly decreased in aged control cells despite decreased proteasomal activity. This finding is related to a decreased polyubiquitination ability due to the impairment of the ubiquitin-activating enzyme in aged control cells, probably related to a more oxidative microenvironment. CR preserves the ubiquitin–proteasome system activity. Overall, we found that aging and CR modulate many aspects of protein modification and turnover.