Solc C K, Zagotta W N, Aldrich R W
Science. 1987 May 29;236(4805):1094-8. doi: 10.1126/science.2437657.
Whole-cell and single-channel voltage-clamp techniques were used to identify and characterize the channels underlying the fast transient potassium current (A current) in cultured myotubes and neurons of Drosophila. The myotube (A1) and neuronal (A2) channels are distinct, differing in conductance, voltage dependence, and gating kinetics. The myotube currents have a faster and more voltage-dependent macroscopic inactivation rate, a larger steady-state component, and a less negative steady-state inactivation curve than the neuronal currents. The myotube channels have a conductance of 12 to 16 picosiemens, whereas the neuronal channels have a conductance of 5 to 8 picosiemens. In addition, the myotube channel is affected by Shaker mutations, whereas the neuronal channel is not. Together, these data suggest that the two channels are separate molecular structures, the expression of which is controlled, at least in part, by different genes.
采用全细胞和单通道电压钳技术来识别和表征果蝇培养肌管和神经元中快速瞬态钾电流（A电流）背后的通道。肌管（A1）通道和神经元（A2）通道是不同的，在电导、电压依赖性和门控动力学方面存在差异。肌管电流具有比神经元电流更快且更依赖电压的宏观失活速率、更大的稳态成分以及更不呈负性的稳态失活曲线。肌管通道的电导为12至16皮西门子，而神经元通道的电导为5至8皮西门子。此外，肌管通道受Shaker突变影响，而神经元通道不受影响。这些数据共同表明，这两种通道是独立的分子结构，其表达至少部分受不同基因控制。
