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The significance of peroxisome function in chronological aging of Saccharomyces cerevisiae.

Lefevre SD, van Roermund CW, Wanders RJ, Veenhuis M, van der Klei IJ - Aging Cell (2013)

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.

View Article: PubMed Central - PubMed

Affiliation: Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, P.O. Box 11103, 9700CC, Groningen, The Netherlands.

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Peroxisome proliferation and β-oxidation during chronological aging of WT cells. (A) Growth curve of WT cells on 0.5% glucose. The data represent mean ± SEM from at least six independent experiments. L, logarithmic phase; D, diauxic phase; PD, postdiauxic phase; ST, stationary phase. (B) Fluorescence microscopy images of WT cells producing GFP-SKL to mark peroxisomes at different time points of a chronological aging experiment. The cell contours are indicated in blue. D-day. (C, D) Western blots, using total crude extracts, decorated with anti-Pex5 (C) or anti-Pot1 (D) antibodies showing the levels of these proteins during chronological aging. Antibodies against mitochondrial porine (Por1) were used as a loading control. The quantification reflects the relative amount of protein. The value at day 15 (D15) was set to 1. Differences in loading were corrected using quantification of the Por1 bands. Values were calculated from two different gels. (E) β-oxidation activities during chronological aging measured as the release of 14C-CO2 by a suspension of whole cells in the presence of 14C-lauric acid. The data represent mean ± SEM, n = 3.
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fig03: Peroxisome proliferation and β-oxidation during chronological aging of WT cells. (A) Growth curve of WT cells on 0.5% glucose. The data represent mean ± SEM from at least six independent experiments. L, logarithmic phase; D, diauxic phase; PD, postdiauxic phase; ST, stationary phase. (B) Fluorescence microscopy images of WT cells producing GFP-SKL to mark peroxisomes at different time points of a chronological aging experiment. The cell contours are indicated in blue. D-day. (C, D) Western blots, using total crude extracts, decorated with anti-Pex5 (C) or anti-Pot1 (D) antibodies showing the levels of these proteins during chronological aging. Antibodies against mitochondrial porine (Por1) were used as a loading control. The quantification reflects the relative amount of protein. The value at day 15 (D15) was set to 1. Differences in loading were corrected using quantification of the Por1 bands. Values were calculated from two different gels. (E) β-oxidation activities during chronological aging measured as the release of 14C-CO2 by a suspension of whole cells in the presence of 14C-lauric acid. The data represent mean ± SEM, n = 3.

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).


The significance of peroxisome function in chronological aging of Saccharomyces cerevisiae.

Lefevre SD, van Roermund CW, Wanders RJ, Veenhuis M, van der Klei IJ - Aging Cell (2013)

Peroxisome proliferation and β-oxidation during chronological aging of WT cells. (A) Growth curve of WT cells on 0.5% glucose. The data represent mean ± SEM from at least six independent experiments. L, logarithmic phase; D, diauxic phase; PD, postdiauxic phase; ST, stationary phase. (B) Fluorescence microscopy images of WT cells producing GFP-SKL to mark peroxisomes at different time points of a chronological aging experiment. The cell contours are indicated in blue. D-day. (C, D) Western blots, using total crude extracts, decorated with anti-Pex5 (C) or anti-Pot1 (D) antibodies showing the levels of these proteins during chronological aging. Antibodies against mitochondrial porine (Por1) were used as a loading control. The quantification reflects the relative amount of protein. The value at day 15 (D15) was set to 1. Differences in loading were corrected using quantification of the Por1 bands. Values were calculated from two different gels. (E) β-oxidation activities during chronological aging measured as the release of 14C-CO2 by a suspension of whole cells in the presence of 14C-lauric acid. The data represent mean ± SEM, n = 3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3824234&req=5

fig03: Peroxisome proliferation and β-oxidation during chronological aging of WT cells. (A) Growth curve of WT cells on 0.5% glucose. The data represent mean ± SEM from at least six independent experiments. L, logarithmic phase; D, diauxic phase; PD, postdiauxic phase; ST, stationary phase. (B) Fluorescence microscopy images of WT cells producing GFP-SKL to mark peroxisomes at different time points of a chronological aging experiment. The cell contours are indicated in blue. D-day. (C, D) Western blots, using total crude extracts, decorated with anti-Pex5 (C) or anti-Pot1 (D) antibodies showing the levels of these proteins during chronological aging. Antibodies against mitochondrial porine (Por1) were used as a loading control. The quantification reflects the relative amount of protein. The value at day 15 (D15) was set to 1. Differences in loading were corrected using quantification of the Por1 bands. Values were calculated from two different gels. (E) β-oxidation activities during chronological aging measured as the release of 14C-CO2 by a suspension of whole cells in the presence of 14C-lauric acid. The data represent mean ± SEM, n = 3.
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).

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.

View Article: PubMed Central - PubMed

Affiliation: Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, P.O. Box 11103, 9700CC, Groningen, The Netherlands.

Show MeSH
Related in: MedlinePlus