School of Engineering and Applied Sciences, Harvard University, Cambridge, United States.
Department of Chemistry, Harvard University, Cambridge, United States.
Elife. 2023 Oct 6;12:RP86833. doi: 10.7554/eLife.86833.
Many channelrhodopsins are permeable to protons. We found that in neurons, activation of a high-current channelrhodopsin, CheRiff, led to significant acidification, with faster acidification in the dendrites than in the soma. Experiments with patterned optogenetic stimulation in monolayers of HEK cells established that the acidification was due to proton transport through the opsin, rather than through other voltage-dependent channels. We identified and characterized two opsins which showed large photocurrents, but small proton permeability, PsCatCh2.0 and ChR2-3M. PsCatCh2.0 showed excellent response kinetics and was also spectrally compatible with simultaneous voltage imaging with QuasAr6a. Stimulation-evoked acidification is a possible source of disruptions to cell health in scientific and prospective therapeutic applications of optogenetics. Channelrhodopsins with low proton permeability are a promising strategy for avoiding these problems.
许多通道蛋白对质子是可渗透的。我们发现，在神经元中，高电流通道蛋白 CheRiff 的激活导致显著酸化，树突中的酸化速度比胞体中快。在 HEK 细胞单层中的图案化光遗传学刺激实验表明，酸化是由于质子通过视蛋白运输，而不是通过其他电压依赖性通道。我们鉴定并表征了两种视蛋白，它们显示出大的光电流，但质子通透性小，即 PsCatCh2.0 和 ChR2-3M。PsCatCh2.0 表现出优异的响应动力学，并且与 QuasAr6a 同时进行电压成像也是兼容的。光遗传学科学和预期治疗应用中，刺激引起的酸化可能会破坏细胞健康。质子通透性低的通道蛋白是避免这些问题的一种有前途的策略。
