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Updated: May 31, 2026

A Suppressor Screen for the Characterization of Genetic Links Regulating Chronological Lifespan in Saccharomyces cerevisiae
Published on: September 17, 2020
Aging and calorie restriction modulate yeast redox state, oxidized protein removal, and the ubiquitin-proteasome
Fernanda Marques da Cunha1, Marilene Demasi, Alicia J Kowaltowski
1Departamento de Bioquímica, Universidade de São Paulo, 05508-900 Cidade Universitária, São Paulo, Brazil.
Abstract:
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.
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