Cryo-EM structures of the channelrhodopsin ChRmine in lipid nanodiscs.
Cryo-EM structures of the channelrhodopsin ChRmine in lipid nanodiscs.
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DOI：
10.1038/s41467-022-32441-7
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发表时间：
2022-08-17
影响因子：
16.6
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微生物通道视紫红质是广泛用于神经元活动的光遗传学操纵的光门控离子通道。ChRmine是一种细菌视紫红质样阳离子通道视紫红质（BCCR），与离子泵视紫红质的关系比其他通道视紫红质更密切。ChRmine显示出有利于光遗传学的独特性质，包括高光敏性、宽的红移激活光谱、阳离子选择性和大的光电流，而其缓慢的闭合动力学阻碍了一些应用。ChRmine功能或任何其他BCCR功能的结构基础尚不清楚。在这里，我们目前的cryo-EM结构的ChRmine在脂质nanodisks在载脂蛋白（视蛋白）和视网膜结合（视紫红质）的形式。这些结构揭示了一种前所未有的三聚体结构，具有脂质填充的中心孔。膜两侧的大电负性空腔促进了高电导率和对阳离子的选择性超过质子。视网膜结合口袋结构表明通道特性可以通过突变来调节，并且我们鉴定了关闭率降低十倍和增加两倍的ChRmine变体。T119 A突变体相对于野生型和先前报道的ChRmine变体显示出用于光遗传学的有利特性。这些结果提供了对产生超强效微生物视蛋白的结构特征的深入了解，并为具有改进特性的通道视紫红质的合理工程提供了平台，这些特性可以扩大光遗传学实验的规模，深度和精度。ChRmine是一种细菌视紫红质样阳离子通道视紫红质（BCCR）。在这里，作者提出了载脂蛋白和视网膜结合形式的ChRmine的cryo-EM结构，以深入了解BCCR中的通道活性，并促进基于ChRmine的光遗传学工具的工程化。
Microbial channelrhodopsins are light-gated ion channels widely used for optogenetic manipulation of neuronal activity. ChRmine is a bacteriorhodopsin-like cation channelrhodopsin (BCCR) more closely related to ion pump rhodopsins than other channelrhodopsins. ChRmine displays unique properties favorable for optogenetics including high light sensitivity, a broad, red-shifted activation spectrum, cation selectivity, and large photocurrents, while its slow closing kinetics impedes some applications. The structural basis for ChRmine function, or that of any other BCCR, is unknown. Here, we present cryo-EM structures of ChRmine in lipid nanodiscs in apo (opsin) and retinal-bound (rhodopsin) forms. The structures reveal an unprecedented trimeric architecture with a lipid filled central pore. Large electronegative cavities on either side of the membrane facilitate high conductance and selectivity for cations over protons. The retinal binding pocket structure suggests channel properties could be tuned with mutations and we identify ChRmine variants with ten-fold decreased and two-fold increased closing rates. A T119A mutant shows favorable properties relative to wild-type and previously reported ChRmine variants for optogenetics. These results provide insight into structural features that generate an ultra-potent microbial opsin and provide a platform for rational engineering of channelrhodopsins with improved properties that could expand the scale, depth, and precision of optogenetic experiments. ChRmine is a bacteriorhodopsin-like cation channelrhodopsin (BCCR). Here, the authors present cryo-EM structures of ChRmine in apo- and retinal-bound forms to provide insight into channel activity in a BCCR and facilitate engineering of ChRmine-based optogenetic tools.
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影响因子：
64.8
作者：
Kim YS;Kato HE;Yamashita K;Ito S;Inoue K;Ramakrishnan C;Fenno LE;Evans KE;Paggi JM;Dror RO;Kandori H;Kobilka BK;Deisseroth K
通讯作者：
Deisseroth K
影响因子：
62.1
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Ernst, Oliver P.;Lodowski, David T.;Elstner, Marcus;Hegemann, Peter;Brown, Leonid S.;Kandori, Hideki
通讯作者：
Kandori, Hideki
影响因子：
13.9
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Fenno L;Yizhar O;Deisseroth K
通讯作者：
Deisseroth K
影响因子：
46.9
作者：
Chen R;Gore F;Nguyen QA;Ramakrishnan C;Patel S;Kim SH;Raffiee M;Kim YS;Hsueh B;Krook-Magnusson E;Soltesz I;Deisseroth K
通讯作者：
Deisseroth K
影响因子：
64.5
作者：
Kishi KE;Kim YS;Fukuda M;Inoue M;Kusakizako T;Wang PY;Ramakrishnan C;Byrne EFX;Thadhani E;Paggi JM;Matsui TE;Yamashita K;Nagata T;Konno M;Quirin S;Lo M;Benster T;Uemura T;Liu K;Shibata M;Nomura N;Iwata S;Nureki O;Dror RO;Inoue K;Deisseroth K;Kato HE
通讯作者：
Kato HE