Surviving in the cold: yeast mutants with extended hibernating lifespan are oxidant sensitive

Abstract

Metabolic activity generates oxidizing molecules throughout life, but it is still debated if the resulting damage of macromolecules is a causality, or consequence, of the aging process. This problem demands for studying growth- and longevity phenotypes separately. Here, we assayed a complete collection of haploid Saccharomyces cerevisiae knock-out strains for their capacity to endure long periods at low metabolic rates. Deletion of 93 genes, predominantly factors of primary metabolism, allowed yeast to survive for more than 58 months in the cold. The majority of these deletion strains were not resistant against oxidants or reductants, but many were hypersensitive. Hence, survival at low metabolic rates has limiting genetic components, and correlates with stress resistance inversely. Indeed, maintaining the energy consuming anti-oxidative machinery seems to be disadvantageous under coldroom conditions.

Keywords: aging; growth rate; metabolism; oxidative stress resistance.

Figure 1.. Oxidant-resistance is not a premise for long-time survival in the cold.

(A) 106 48-position agar plates containing a systematic yeast knock-out collection were incubated at 4°C and replicated after 12 and 58 months, respectively. (B) GO analysis of surviving strains; the majority groups to metabolic processes (C) Comprehensive phenotypic analysis of mutants that survived for 58 months in the cold. Resistance to oxidants or reductants is the exception.