Fig. 2.

CaMKII facilitates CaM’s effect on channel activity. Ca²⁺ channel activity was recorded in CHO cells expressing wild type (w.t.) α1C and β2a in the cell-attached and inside-out mode. The open-state probability (NP _o) of the channels for each repetitive depolarization was plotted against time. A Application of CaM (1 μM) + ATP (3 mM) 1 min after patch excision (shown by i.o. and an arrow) restored channel activity. B Channel activity was relatively low when CaM + ATP were applied 5 min after patch excision, indicating time-dependent attenuation of the CaM’s effect. C Application of CaMKIIT286D (1 μM) + ATP (3 mM) in the inside-out mode produced channel activity at a low level and retained the CaM’s effect. Examples of current traces recorded in the cell-attached mode (a) and during application of CaMKIIT286D + ATP (b) and CaM + ATP (c) in the inside-out mode are shown