Background: Cyclin D1 is immediately down-regulated in response to reactive oxygen species (ROS) and implicated in the induction of cell cycle arrest in G2 phase by an unknown mechanism. Either treatment with a protease inhibitor alone or expression of protease-resistant cyclin D1 T286A resulted in only a partial relief from the ROS-induced cell cycle arrest, indicating the presence of an additional control mechanism.
Methods: Cells were exposed to hydrogen peroxide (H2O2), and analyzed to assess the changes in cyclin D1 level and its effects on cell cycle processing by kinase assay, de novo synthesis, gene silencing, and polysomal analysis, etc.
Results: Exposure of cells to excessive H2O2 induced ubiquitin-dependent proteasomal degradation of cyclin D1, which was subsequently followed by translational repression. This dual control mechanism was found to contribute to the induction of cell cycle arrest in G2 phase under oxidative stress. Silencing of an eIF2α kinase PERK significantly retarded cyclin D1 depletion, and contributed largely to rescuing cells from G2 arrest. Also the cyclin D1 level was found to be correlated with Chk1 activity.
Conclusions: In addition to an immediate removal of the pre-existing cyclin D1 under oxidative stress, the following translational repression appear to be required for ensuring full depletion of cyclin D1 and cell cycle arrest. Oxidative stress-induced cyclin D1 depletion is linked to the regulation of G2/M transit via the Chk1-Cdc2 DNA damage checkpoint pathway.
General Significance: The control of cyclin D1 is a gate keeping program to protect cells from severe oxidative damages.
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http://dx.doi.org/10.1016/j.bbagen.2013.07.030 | DOI Listing |
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Universitätsklinikum Heidelberg, Med. Klinik V, GMMG-Studygroup, Heidelberg, Germany.
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Department of Biochemistry, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, ul. Lwowska 1, 87-100 Torun, Poland.
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Institute of Sport Sciences, Jerzy Kukuczka Academy of Physical Education in Katowice, Katowice, Poland.
Curcumin is known for its potential health benefits; however, the evidence remains inconclusive regarding its necessity as a supplement for athletes during the preparatory phase of training. This study aimed to assess the effect of 6-week curcumin supplementation at a dose of 2g/day on selected inflammatory markers, blood count, and brain-derived neurotropic factor (BDNF) levels in middle-aged amateur long-distance runners during the preparatory period of a macrocycle. Thirty runners were randomly assigned to either a curcumin-supplemented group (CUR, n = 15) or a placebo group (PLA, n = 15).
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January 2025
South African Grape and Wine Research Institute, Stellenbosch University, Stellenbosch, South Africa.
Hyphopichia pseudoburtonii, is emerging as a potential biocontrol agent against various phytopathogens. These traits have been attributed to the production of various antifungal compounds in the presence of target pathogens. However, the broad molecular mechanisms involved in the antifungal activity are not yet understood.
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Department of Biology, Damghan Branch, Islamic Azad University, Damghan, Iran.
5-FU is a widely used chemotherapy drug for esophageal carcinomas, but therapy failure has been observed in 5-FU-resistant patients. Overcoming this resistance is a significant challenge in cancer treatment, requiring identifying and targeting important resistance mechanisms. PYGO2 expression is crucial in developing resistance to various chemotherapy drugs.
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