Cooperative subunit interactions in C-type inactivation of K channels
Cooperative subunit interactions in C-type inactivation of K channels
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DOI：
10.1016/s0006-3495(95)80114-1
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发表时间：
1995-12-01
影响因子：
3.4
通讯作者：
Aldrich, RW
中科院分区：
文献类型：
--
作者：
Ogielska, EM;Zagotta, WN;Aldrich, RW
钾通道的C型失活与N-末端介导的（N型）失活不同，涉及通道外口的关闭。我们通过比较由不同亚基组合构建的通道的失活速率，研究了四聚体通道的单个亚基在C型失活构象变化中的作用。失活速率与快亚基数目之间的关系是指数关系，这可以通过C型构象变化涉及所有四个亚基的协同机制来预测，并且排除了任何单个亚基中的构象变化足以失活的机制。C型失活中的亚基相互作用进一步得到影响C型失活的单独突变之间的相互作用的支持，当在相同或单独的亚基中时。
C-type inactivation of potassium channels is distinct from N-terminal mediated (N-type) inactivation and involves a closing of the outer mouth of the channel. We have investigated the role of the individual subunits of the tetrameric channel in the C-type inactivation conformational change by comparing the inactivation rates of channels constructed from different combinations of subunits, The relationship between the inactivation rate and the number of fast subunits is exponential, as would be predicted by a cooperative mechanism where the C-type conformational change involves all four subunits, and rules out a mechanism where a conformational change in any of the individual subunits is sufficient for inactivation. Subunit interactions in C-type inactivation are further supported by an interaction between separate mutations affecting C-type inactivation when in either the same or separate subunits.