Subunit stoichiometry of the CNG channel of rod photoreceptors
Subunit stoichiometry of the CNG channel of rod photoreceptors
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DOI：
10.1016/s0896-6273(02)01098-x
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发表时间：
2002-12-05
期刊：
影响因子：
16.2
通讯作者：
Kaupp, UB
中科院分区：
文献类型：
--
作者：
Weitz, D;Ficek, N;Kaupp, UB
环核苷酸门控(CNG)通道在感觉刺激到电信号的转换中起着核心作用。CNG通道形成由A和B亚基组成的异源低聚复合体。在这里，我们用化学交联法研究了天然棒状CNG通道的亚基化学计量。用SDS-PAGE测定各交联物的表观分子量(M-w)，用针对A1或B1亚基的抗体进行免疫印迹分析其组成。根据交联物的数量及其M-w，以及交联物中A1和B1亚基的免疫学鉴定，我们得出结论：天然杆状CNG通道是由3个A1和1个B1亚基组成的四聚体。这是四聚体通道中对称性破坏的一个例子。
Cyclic nucleotide-gated (CNG) channels play a central role in the conversion of sensory stimuli into electrical signals. CNG channels form heterooligomeric complexes built of A and B subunits. Here, we study the subunit stoichiometry of the native rod CNG channel by chemical crosslinking. The apparent molecular weight (M-w) of each crosslink product was determined by SDS-PAGE, and its composition was analyzed by Western blotting using antibodies specific for the A1 or B1 subunit. The number of crosslink products and their M-w as well as the immunological identification of A1 and B1 subunits in the crosslink products led us to conclude that the native rod CNG channel is a tetramer composed of three A1 and one B1 subunit. This is an example of violation of symmetry in tetrameric channels.