hERG potassium channel gating is mediated by N- and C-terminal region interactions.
hERG potassium channel gating is mediated by N- and C-terminal region interactions.
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DOI：
10.1085/jgp.201010582
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发表时间：
2011-03
期刊：
影响因子：
--
通讯作者：
Trudeau MC
中科院分区：
文献类型：
--
作者：
Gustina AS;Trudeau MC
人类ether-á-go-go-related基因（hERG）钾通道具有异常缓慢的电压依赖性关闭（失活）动力学。hERG胞质N端区域的Per-Arnt-Sim（PAS）结构域通过与hERG通道的另一部分直接相互作用来调节缓慢失活。然而，缓慢失活的机制尚不清楚，因为参与失活调节的通道的其他区域尚不清楚。为了鉴定缓慢失活的其他功能决定因素，我们产生了细胞质C-末端区域缺失的hERG通道。我们报告说，hERG通道与删除的环核苷酸结合结构域（CNBD）有加速失活动力学，在hERG通道中看到的PAS结构域缺乏类似。通道与PAS结构域和CNBD的双重缺失没有表现出进一步加速失活，表明PAS结构域和CNBD调节失活的收敛机制。我们先前显示的重组PAS结构域可以直接调节PAS结构域缺失的通道，但不能调节PAS结构域和CNBD双重缺失的通道，这表明PAS结构域不与CNBD缺失的通道相互作用。生化蛋白质相互作用分析表明，谷胱甘肽S-转移酶（GST）-PAS（但不是GST）结合到CNBD的融合蛋白。PAS结构域缺失的亚基（具有完整的C-末端区域）和CNBD缺失的亚基（具有完整的N-末端区域）的共表达导致通道部分恢复缓慢失活动力学，表明PAS结构域和CNBD之间的调节亚基间相互作用。总之，这些数据表明，在hERG通道中的缓慢失活的调节机制是N-末端PAS结构域和C-末端CNBD之间的相互作用。
Human ether-á-go-go–related gene (hERG) potassium channels have voltage-dependent closing (deactivation) kinetics that are unusually slow. A Per-Arnt-Sim (PAS) domain in the cytoplasmic N-terminal region of hERG regulates slow deactivation by making a direct interaction with another part of the hERG channel. The mechanism for slow deactivation is unclear, however, because the other regions of the channel that participate in regulation of deactivation are not known. To identify other functional determinants of slow deactivation, we generated hERG channels with deletions of the cytoplasmic C-terminal regions. We report that hERG channels with deletions of the cyclic nucleotide–binding domain (CNBD) had accelerated deactivation kinetics that were similar to those seen in hERG channels lacking the PAS domain. Channels with dual deletions of the PAS domain and the CNBD did not show further acceleration in deactivation, indicating that the PAS domain and the CNBD regulate deactivation by a convergent mechanism. A recombinant PAS domain that we previously showed could directly regulate PAS domain–deleted channels did not regulate channels with dual deletions of the PAS domain and CNBD, suggesting that the PAS domain did not interact with CNBD-deleted channels. Biochemical protein interaction assays showed that glutathione S-transferase (GST)–PAS (but not GST) bound to a CNBD-containing fusion protein. Coexpression of PAS domain–deleted subunits (with intact C-terminal regions) and CNBD-deleted subunits (with intact N-terminal regions) resulted in channels with partially restored slow deactivation kinetics, suggesting regulatory intersubunit interactions between PAS domains and CNBDs. Together, these data suggest that the mechanism for regulation of slow deactivation in hERG channels is an interaction between the N-terminal PAS domain and the C-terminal CNBD.
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DOI：
10.1085/jgp.112.5.637
发表时间：
1998-11
期刊：
The Journal of general physiology
影响因子：
--
作者：
Wang J;Trudeau MC;Zappia AM;Robertson GA
通讯作者：
Robertson GA
影响因子：
64.5
作者：
Cabral, JHM;Lee, A;Mackinnon, R
通讯作者：
Mackinnon, R
影响因子：
5.5
作者：
Pessia, Mauro;Servettini, Ilenio;Pettorossi, Vito Enrico
通讯作者：
Pettorossi, Vito Enrico
影响因子：
56.9
作者：
Varnum, MD;Zagotta, WN
通讯作者：
Zagotta, WN
影响因子：
3.4
作者：
Viloria, CG;Barros, F;de la Peña, P
通讯作者：
de la Peña, P