AI Insight
This study reveals that the checkpoint kinase Rad53/Chk2 plays a previously unknown role in coordinating mitochondrial function and cellular redox balance with cell cycle progression in yeast. Researchers found that loss of Rad53 causes cells to accumulate in the G2/M phase of the cell cycle, accompanied by disrupted mitochondrial metabolism, increased TCA cycle activity, altered electron transport chain protein levels, elevated mitochondrial membrane potential, and increased reactive oxygen species (ROS). Treatment with antioxidants rescued the cell division defects, demonstrating that elevated ROS is the primary cause of the cell cycle abnormalities when Rad53 is absent.
Why it matters
These findings establish a fundamental link between checkpoint kinase function, metabolic regulation, and cell cycle control during normal cell growth. Since Chk2 is conserved in humans and frequently mutated in cancer, understanding how it coordinates metabolism with cell division could inform therapeutic strategies targeting the metabolic vulnerabilities of cancer cells.
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⚠️ Preprint – Noch nicht peer-reviewed
Dieser Artikel wurde noch nicht von unabhängigen Experten begutachtet. Die Ergebnisse sind vorläufig und sollten mit Vorsicht interpretiert werden.
Cell-cycle progression requires coordination with cellular metabolism, yet how checkpoint kinases contribute to this coordination during normal growth remains poorly understood. Here, we uncover an unexpected role for the checkpoint kinase Rad53/Chk2 in coupling mitochondrial and redox homeostasis to G2/M progression. In prototrophic S. cerevisiae, Rad53 loss (rad53{Delta}) disrupts cell-cycle progression and causes cells to accumulate in G2/M, alongside extensive metabolic remodelling with increased tricarboxylic acid (TCA) cycle flux. Mitochondrial proteomics reveals altered relative abundances of individual electron transport chain proteins, and mitochondrial membrane potential increases without increased oxygen consumption or ATP generation. This altered mitochondrial state is associated with elevated reactive oxygen species (ROS) and oxidative stress. Genetic analyses establish that mitochondrial phenotypes require Rad53 kinase activity and are distinct from the loss of SML1. Antioxidant treatment rescues cell-division, budding defects and the accumulation of abnormally sized cells, establishing ROS as a primary cause of cell-cycle defects. Thus, Rad53 couples mitochondrial and redox homeostasis to G2/M progression during normal growth.
Source: Rad53/Chk2 couples mitochondrial outputs and ROS with G2/M cell cycle progression