Identification and characterization of hydrophobic gate residues in TRP channels.
Identification and characterization of hydrophobic gate residues in TRP channels.
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TRP 通道中疏水门残基的鉴定和表征。
DOI：
10.1096/fj.201700599rr
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Chen Xing-Zhen
中科院分区：
文献类型：
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作者：
Zheng Wang;Hu Ruikun;Cai Ruiqi;Hofmann Laura;Hu Qiaolin;Fatehi Mohammad;Long Wentong;Kong Tim;Tang Jingfeng;Light Peter;Flockerzi Veit;Cao Ying;Chen Xing-Zhen
瞬时受体电位 (TRP) 通道在哺乳动物中分为 6 个亚科，在感觉生理学中具有重要作用。它们通过通道门的打开或关闭对非常不同的刺激做出反应，包括热、化学和机械方式。在本研究中，我们系统地用亲水残基取代了孔衬螺旋S6远端片段内的疏水残基，并基于爪蟾细胞和哺乳动物细胞电生理学以及疏水门理论，鉴定了TRPV6/V5/V4/C4/M8中的疏水门。我们发现，当 TRPV6Ala616 或 Met617 或 TRPV5Ala576 或 Met577（但不是其任何相邻残基）被亲水残基取代时，通道活性急剧增加。通道活性与这些位点残基的亲水性密切相关，表明连续的疏水性残基TRPV6Ala616-Met617和TRPV5Ala576-Met577在每个通道中形成双残基门。通过相同的策略，我们在 TRPV4Iso715、TRPC4Iso617 和 TRPM8Val976 中鉴定了疏水性单残基门。支持疏水门理论，门位点的亲水取代消除了疏水门密封，显着增加了低活性状态下 TRP 通道的活性，但对激活通道的功能几乎没有影响。与单残基门通道相比，双残基门通道对门疏水性或尺寸的微小变化更敏感。 TRP 通道中非常规的双驻门控机制可能已经进化为特别对触发相对较小的门构象变化的生理刺激做出反应。—Zheng, W., Hu, R., Cai, R., Hofmann, L., Hu, Q., Fatehi, M., Long, W., Kong, T., Tang, J., Light, P., Flockerzi, V., Cao, Y., Chen, X.-Z. TRP 通道中疏水门残基的鉴定和表征。FASEB J.32, 639–653 (2018)。 www.fasebj.org
Transient receptor potential (TRP) channels, subdivided into 6 subfamilies in mammals, have essential roles in sensory physiology. They respond to remarkably diverse stimuli, comprising thermal, chemical, and mechanical modalities, through opening or closing of channel gates. In this study, we systematically substituted the hydrophobic residues within the distal fragment of pore‐lining helix S6 with hydrophilic residues and, based onXenopusoocyte and mammalian cell electrophysiology and a hydrophobic gate theory, identified hydrophobic gates in TRPV6/V5/V4/C4/ M8. We found that channel activity drastically increased when TRPV6Ala616 or Met617or TRPV5Ala576 or Met577, but not any of their adjacent residues, was substituted with hydrophilic residues. Channel activity strongly correlated with the hydrophilicity of the residues at those sites, suggesting that consecutive hydrophobic residues TRPV6Ala616‐Met617and TRPV5Ala576‐Met577form a double‐residue gate in each channel. By the same strategy, we identified a hydrophobic single‐residue gate in TRPV4Iso715, TRPC4Iso617, and TRPM8Val976. In support of the hydrophobic gate theory, hydrophilic substitution at the gate site, which removes the hydrophobic gate seal, substantially increased the activity of TRP channels in low‐activity states but had little effect on the function of activated channels. The double‐residue gate channels were more sensitive to small changes in the gate's hydrophobicity or size than single‐residue gate channels. The unconventional double‐reside gating mechanism in TRP channels may have been evolved to respond especially to physiologic stimuli that trigger relatively small gate conformational changes.—Zheng, W., Hu, R., Cai, R., Hofmann, L., Hu, Q., Fatehi, M., Long, W., Kong, T., Tang, J., Light, P., Flockerzi, V., Cao, Y., Chen, X.‐Z. Identification and characterization of hydrophobic gate residues in TRP channels.FASEB J.32, 639–653 (2018). www.fasebj.org