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Sch9 regulates intracellular protein ubiquitination by controlling stress responses.

Qie B, Lyu Z, Lyu L, Liu J, Gao X, Liu Y, Duan W, Zhang N, Du L, Liu K - Redox Biol (2015)

Bottom Line: In this study, we found that the overall level of ubiquitinated proteins dramatically decreased as yeast cell grew from log to stationary phase.Deletion of SCH9, a gene encoding a key protein kinase for longevity control, decreased the level of ubiquitinated proteins in log phase and this effect could be reversed by restoring Sch9 function.Our results revealed for the first time how Sch9 regulates the level of ubiquitinated proteins and provides new insight into how Sch9 controls longevity.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Science, Sichuan University, Chengdu, Sichuan 610064, China.

No MeSH data available.


Related in: MedlinePlus

H2O2 contributes to the enhanced intracellular oxidation and ubiquitination of sch9Δ cells. (A, B) Microscopy (A) or spectrofluorimeter analysis (B) of DCF fluorescence on WT (TB50a) and sch9Δ (TS120-2d) cells transformed with pEGH-CTT1 or control vector with or without 1 hour treatment of 0.5 mM H2O2. Bars: 100 µm. (C–F) WT and sch9Δ cells were treated with or without H2O2 at indicated concentrations for 1 h and the total ubiquitination were tested by western blotting (C, E) with respective quantifications (D, F). (G) Spectrofluorimeter analysis of DCF- or DHR123-stained cells with or without treatment of H2O2 at indicated concentrations for 1 hour (All cells were collected at log phase with an OD600 nm of 0.5. *P < 0.05, **p < 0.01, “ns” no significance).
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f0025: H2O2 contributes to the enhanced intracellular oxidation and ubiquitination of sch9Δ cells. (A, B) Microscopy (A) or spectrofluorimeter analysis (B) of DCF fluorescence on WT (TB50a) and sch9Δ (TS120-2d) cells transformed with pEGH-CTT1 or control vector with or without 1 hour treatment of 0.5 mM H2O2. Bars: 100 µm. (C–F) WT and sch9Δ cells were treated with or without H2O2 at indicated concentrations for 1 h and the total ubiquitination were tested by western blotting (C, E) with respective quantifications (D, F). (G) Spectrofluorimeter analysis of DCF- or DHR123-stained cells with or without treatment of H2O2 at indicated concentrations for 1 hour (All cells were collected at log phase with an OD600 nm of 0.5. *P < 0.05, **p < 0.01, “ns” no significance).

Mentions: H2O2 is a major intracellular ROS which emerged as a central hub in redox signaling and oxidative stress [52]. The enhanced CTT1 expression in sch9Δ cells suggest that the lower protein ubiquitination and oxidative stress may be contributed by the lower H2O2 level. To unveil if the difference of intracellular redox statuses between WT and sch9Δ cells is related to the different levels of intracellular H2O2, the oxidation of DCF and DHR123 in both strains was compared in the presence or absence of elevated catalase T activity. By overexpressing Ctt1 in WT cells, the catalase T activity was elevated to a level similar to that in sch9Δ cells (Fig. S4A and B) and the oxidation of DCF and DHR123 was decreased ~20% and ~30% respectively (Figs. 5A and B, and S5A and B). However, enhancing the catalase T activity in sch9Δ cells did not further decrease the oxidation unless exogenous H2O2 was added into the cell culture (Figs. 5A and B, and S5A and B). These results suggest that the enhanced H2O2 removal in sch9Δ cells contribute to their alleviated oxidative stress.


Sch9 regulates intracellular protein ubiquitination by controlling stress responses.

Qie B, Lyu Z, Lyu L, Liu J, Gao X, Liu Y, Duan W, Zhang N, Du L, Liu K - Redox Biol (2015)

H2O2 contributes to the enhanced intracellular oxidation and ubiquitination of sch9Δ cells. (A, B) Microscopy (A) or spectrofluorimeter analysis (B) of DCF fluorescence on WT (TB50a) and sch9Δ (TS120-2d) cells transformed with pEGH-CTT1 or control vector with or without 1 hour treatment of 0.5 mM H2O2. Bars: 100 µm. (C–F) WT and sch9Δ cells were treated with or without H2O2 at indicated concentrations for 1 h and the total ubiquitination were tested by western blotting (C, E) with respective quantifications (D, F). (G) Spectrofluorimeter analysis of DCF- or DHR123-stained cells with or without treatment of H2O2 at indicated concentrations for 1 hour (All cells were collected at log phase with an OD600 nm of 0.5. *P < 0.05, **p < 0.01, “ns” no significance).
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

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Show All Figures
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f0025: H2O2 contributes to the enhanced intracellular oxidation and ubiquitination of sch9Δ cells. (A, B) Microscopy (A) or spectrofluorimeter analysis (B) of DCF fluorescence on WT (TB50a) and sch9Δ (TS120-2d) cells transformed with pEGH-CTT1 or control vector with or without 1 hour treatment of 0.5 mM H2O2. Bars: 100 µm. (C–F) WT and sch9Δ cells were treated with or without H2O2 at indicated concentrations for 1 h and the total ubiquitination were tested by western blotting (C, E) with respective quantifications (D, F). (G) Spectrofluorimeter analysis of DCF- or DHR123-stained cells with or without treatment of H2O2 at indicated concentrations for 1 hour (All cells were collected at log phase with an OD600 nm of 0.5. *P < 0.05, **p < 0.01, “ns” no significance).
Mentions: H2O2 is a major intracellular ROS which emerged as a central hub in redox signaling and oxidative stress [52]. The enhanced CTT1 expression in sch9Δ cells suggest that the lower protein ubiquitination and oxidative stress may be contributed by the lower H2O2 level. To unveil if the difference of intracellular redox statuses between WT and sch9Δ cells is related to the different levels of intracellular H2O2, the oxidation of DCF and DHR123 in both strains was compared in the presence or absence of elevated catalase T activity. By overexpressing Ctt1 in WT cells, the catalase T activity was elevated to a level similar to that in sch9Δ cells (Fig. S4A and B) and the oxidation of DCF and DHR123 was decreased ~20% and ~30% respectively (Figs. 5A and B, and S5A and B). However, enhancing the catalase T activity in sch9Δ cells did not further decrease the oxidation unless exogenous H2O2 was added into the cell culture (Figs. 5A and B, and S5A and B). These results suggest that the enhanced H2O2 removal in sch9Δ cells contribute to their alleviated oxidative stress.

Bottom Line: In this study, we found that the overall level of ubiquitinated proteins dramatically decreased as yeast cell grew from log to stationary phase.Deletion of SCH9, a gene encoding a key protein kinase for longevity control, decreased the level of ubiquitinated proteins in log phase and this effect could be reversed by restoring Sch9 function.Our results revealed for the first time how Sch9 regulates the level of ubiquitinated proteins and provides new insight into how Sch9 controls longevity.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Science, Sichuan University, Chengdu, Sichuan 610064, China.

No MeSH data available.


Related in: MedlinePlus