Meltzer J, Santos-Sacchi J
Section of Otolaryngology, Yale University School of Medicine, New Haven, CT 06510, USA.
Neurosci Lett. 2001 Nov 9;313(3):141-4. doi: 10.1016/s0304-3940(01)02266-2.
The transmembrane motor protein prestin is thought to underlie outer hair cell (OHC) motility. Prestin expressed in non-auditory cells confers OHC-like electrical characteristics to the cell membrane, including the generation of gating-like currents (or non-linear capacitance), whose voltage dependence is susceptible to membrane tension and initial voltage conditions. Here we report that prestin's voltage sensitivity is, like that of the native motor, markedly temperature dependent. Prestin-transfected HEK cells were whole-cell voltage clamped while temperature was varied from 10-35 degrees C. V(pkcm), the voltage at peak capacitance, reversibly and linearly shifted to depolarized levels with increasing temperatures, while peak capacitance also increased, but with significant hysteresis upon recooling. Mathematical modeling suggests that this increase may be due to a charged voltage sensor having a wider range of movement through or larger unit charge within the plasma membrane at higher temperatures.
跨膜运动蛋白prestin被认为是外毛细胞（OHC）运动的基础。在非听觉细胞中表达的prestin赋予细胞膜类似OHC的电学特性，包括产生门控样电流（或非线性电容），其电压依赖性易受膜张力和初始电压条件的影响。在此我们报告，prestin的电压敏感性与天然运动蛋白一样，明显依赖于温度。在温度从10 - 35摄氏度变化时，对转染了prestin的HEK细胞进行全细胞电压钳制。电容峰值处的电压V(pkcm)随着温度升高可逆且线性地向去极化水平移动，而电容峰值也增加，但在重新冷却时存在明显的滞后现象。数学建模表明，这种增加可能是由于带电荷的电压传感器在较高温度下在质膜内具有更宽的移动范围或更大的单位电荷。
