Saccharomyces cerevisiae is an optimal model to study stress responses for various reasons: i)
budding yeast genome presents a high degree of homology with the human genome; ii) there are many proteins
that show an elevated functional homology with specific human proteins; iii) it is a system whose genetic
manipulation is reasonably easy and cheaper than other models; iv) the possibility of working with an
haploid state facilitates the study of multiple processes; v) databases are the most complete of all the eukaryotic
models. Due to the latest information derived from proteomic and genomic analyses, the genetic, biochemical
and molecular information available relative to this biological system is extraordinarily big and complete. In this
review, we present an overview of the mechanisms unravelling sensing and transducing oxidative stress. TOR, RAS/PKA,
CWI, SNF1, and HOG are the main pathways involved both in the oxidative response and in the correct entry in stationary
phase. In general, TOR and RAS/PKA dowregulation and SNF1 and CWI upregulation favour both a correct defence
against oxidative damage and the entry in the quiescent state. All of these pathways have counterparts in humans. The actin
cytoskeleton plays a dual function as sensor and target of oxidation, in tight connection with the former signalling cascades.
In budding yeast, progression through stationary phase and quiescence constitute an accepted current model to
study some of the mechanisms that determine life span. Aging is a process associated to oxidative stress and it is in tight
relationship with bulk autophagy and mitophagy, both are mechanisms belonging to the oxidative defence and promoters
of life extension when correctly regulated by, among other elements, the signalling cascades.
Keywords: Aging, CWI pathway, glutaredoxins, MAPK, mitophagy, oxidative-stress, signalling, TOR.
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