The significance of peroxisome function in chronological aging of Saccharomyces cerevisiae.
Bottom Line: We show that intact peroxisomes are an important factor in yeast chronological aging because all pex mutants showed a reduced chronological lifespan.The strongest reduction was observed in Δpex5 cells.Our data indicate that this is related to the complete inactivation of the peroxisomal β-oxidation pathway in these cells due to the mislocalization of thiolase.
Affiliation: Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, P.O. Box 11103, 9700CC, Groningen, The Netherlands.Show MeSH
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Mentions: In order to elucidate the principles of the shorter CSL of pex mutants relative to the WT control, as well as the mutual differences between the pex mutants studied, we investigated the fate of peroxisomes during chronological aging in WT cells. The growth curve of S. cerevisiae on 0.5% glucose starts with a short lag phase followed by logarithmic growth (2–10 h/0.4 days) and progresses through the diauxic shift (10–13 h/0.4–0.55 days) to the postdiauxic (13–48 h/0.55–2 days) and stationary phase (Fig. 3A). Using GFP-SKL as peroxisomal matrix marker, we observed that peroxisomes proliferate from 2.08 ± 0.87 per cell to 4.07 ± 1.29 per cell between 24 h (D1) and 48 h (D2), that is, during the late postdiauxic phase (Fig. 3B). Interestingly, in stationary phase cells, peroxisomes appear clustered in some cells, but remain detectable by fluorescence until 16 days (Fig. 3B).
Affiliation: Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, P.O. Box 11103, 9700CC, Groningen, The Netherlands.