Abstract

The study of aging captured the interest of many researchers as the accumulation of old cells appeared to be linked to several chronic age-related diseases. Despite the complexity of the aging process, the pathways underlying cellular aging were revealed with the help of molecular analyses using the budding yeast Saccharomyces cerevisiae. This model is a unicellular eukaryote that is intensively used in aging research as its mechanisms are evolutionarily conserved across phyla. Our laboratory focused on one of those pathways, namely target of rapamycin type 1 (TOR1) signal transduction network that regulates cell growth in response to the availability of nutrients and growth factors. As such, the TOR1 signaling network activates several pro-aging processes and inhibits some anti-aging processes. Genetic, dietary, or pharmacological manipulations suppressing TOR1 activity have been shown to extend the lifespan. Thus, the single-gene deletion mutant tor1Δ has been used to investigate the mitochondrial proteome using non-caloric restriction. Mitochondrial functionality is vital as their decline is a hallmark of cellular aging in evolutionarily distant eukaryotes. Mitochondria synthesize the bulk of cellular ATP by harboring pathways that link the tricarboxylic acid cycle and oxidative phosphorylation. Mitochondrial fusion and fission are essential contributors to mitochondrial functionality maintenance because they regulate the age-related changes in mitochondria assembly and biogenesis. Mass spectrometry was used to identify and quantify the purified mitochondrial proteins from differently aged control wild-type and tor1Δ mutant strains of budding yeast that were upregulated or downregulated. These findings suggest that some of the mitochondrial proteins in the tor1Δ mutant strain are upregulated and could contribute to the mechanism that extends lifespan in yeast cells.