Cell-cycle-dependent regulation of Ca2+-activated K+ channel in Jurkat T-lymphocyte.
Small-conductance Ca2+-activated K+ (SK2) channel plays an important role in the activation of Jurkat T-lymphocytes by maintaining electrical gradients for the sustained Ca2+ influx. Apamin-sensitive K+ current was significantly decreased with cell-cycle progression from G0/G1 into G2/M phases, and protein expression of SK2 channels showed parallel down-regulation, with its highest expression at early G0/G1 phase. In the G0/G1 phase, the apamin-sensitive component of thapsigargin-induced Ca2+ influx was significantly larger than that in the G2/M phase. These observations suggest that SK2-channel activation may largely contribute to the sustained Ca2+ influx in the G0/G1 phase in comparison of that in the G2/M phase in Jurkat T-lymphocytes.
Morimoto
Takashi
T
Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Japan.
Ohya
Susumu
S
Hayashi
Hidetoshi
H
Onozaki
Kikuo
K
Imaizumi
Yuji
Y
D001030:Apamin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D016193:G1 Phase / Q000502:physiology*; D006801:Humans; D019169:Jurkat Cells; D008564:Membrane Potentials / Q000187:drug effects; D018408:Patch-Clamp Techniques; D024681:Potassium Channels, Calcium-Activated / Q000378:metabolism / Q000502:physiology*; D016192:Resting Phase, Cell Cycle / Q000502:physiology*; D019284:Thapsigargin / Q000494:pharmacology
D024681:Potassium Channels, Calcium-Activated; D001030:Apamin; D019284:Thapsigargin; D002118:Calcium