Change in density of K+ current of HeLa cells during the cell cycle

We investigated the cell cycle-dependency of the channel, using cells synchronized by harvesting them at the mitotic stage. The inward K+ currents by whole-cell patch-clamp were highest in early G1, and then decreased with time to a minimum in the S phase, increasing again in the M phase. In contrast, membrane surface area increases with progression of the cell cycle, whereas the currents decreases from early G1 to an apparent minimum in the S phase. Therefore, the densities of K+ current at fixed membrane potentials were highest in early G1 phase and lowest in the S phase.