Fig. 4
From: Cell cycle progression is regulated by intertwined redox oscillators
Intracellular pH variation and metabolic activity through the cell cycle. Resting cells have been shown to have a basal oxidative metabolism and a pHi around 7. Cells committed to enter G1 exhibit a transient acidic pH followed by cytosolic alkalinization. Increased pHi has been correlated with histone acetylation allowing for DNA accessibility to RNA polymerase and protein synthesis. A pHi threshold of 7.2 has been reported for DNA synthesis in S phase. This is followed by pHi decrease in late S phase and meet optimal ATP synthesis in mitochondria. Follows lipid synthesis in G2. It has been suggested that a pHi drop during mitosis is linked to microtubule disassembly by ATP hydrolysis. This results in histone deacetylation, DNA compaction and chromosome segregation