Topology of the selectivity filter of a TRPV channel:: rapid accessibility of contiguous residues from the external medium
Topology of the selectivity filter of a TRPV channel:: rapid accessibility of contiguous residues from the external medium
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DOI：
10.1152/ajpcell.00406.2007
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发表时间：
2007-12-01
影响因子：
5.5
通讯作者：
Parent, Lucie
中科院分区：
文献类型：
--
作者：
Dodier, Yolaine;Dionne, Francois;Parent, Lucie
瞬时受体电位型V5（TRPV5）通道是一种对Ca 2+具有高度选择性的六跨膜结构域离子通道。为了使用取代的半胱氨酸可及性方法（SCAM）研究选择性过滤器的拓扑结构，使用将控制通道与携带半胱氨酸的亚基串联偶联的二聚体构建体将位置541 - 547处的半胱氨酸突变体作为异源四聚体进行研究。二聚体构建体D542C、G543C、P544C、A545C和Y547C的全细胞电流被带正电荷的2-氨基-3-甲基-N-（2-氨基-3-甲基-N-（2-氨基-3-甲基-N-（2-氨基-3-甲基-N-（2-氨基-3-甲基-N-甲基-N-（2-氨基-3-甲基-N-甲基-N-（2-氨基-3-甲基-N-甲基-N-（2-氨基-3-甲基-N-（2-甲基-N-甲基-N-（2-甲基-N-甲基-N-（2-甲基-N-甲基-N-（2-甲基-N-N-甲基-N-（2-甲基-N-甲基-N-N-（2-甲基-N-N-甲基-N-N-甲基-N-N-（2-甲基-N-N-甲基-N-N-（2-甲基-N-N-甲基-N-（三甲基铵）甲基甲烷硫代磺酸盐溴化物（MTSMT），2-（氨乙基）甲烷硫代磺酸盐溴化物（MTSEA），和2-（三甲基铵）乙基甲烷硫代磺酸盐溴化物（MTSET）试剂，而D542 C、P544 C和A545 C仅被带负电荷的2-（磺酸根合乙基）甲烷硫代磺酸钠（MTSES）抑制。相反，I541C二聚体对阳性和阴性试剂保持不敏感。然而，I541C/D542G和I541C/D542N二聚体构建体快速地（
The transient receptor potential type V5 (TRPV5) channel is a six-transmembrane domain ion channel that is highly selective to Ca2+. To study the topology of the selectivity filter using the substituted cysteine accessibility method (SCAM), cysteine mutants at positions 541-547 were studied as heterotetramers using dimeric constructs that couple the control channel in tandem with a cysteine-bearing subunit. Whole cell currents of dimeric constructs D542C, G543C, P544C, A545C, and Y547C were rapidly inhibited by positively charged 2-(trimethyl ammonium) methyl methane thiosulfonate bromide (MTSMT), 2-(aminoethyl) methane thiosulfonate bromide (MTSEA), and 2-(trimethyl ammonium) ethyl methane thiosulfonate bromide (MTSET) reagents, whereas D542C, P544C, and A545C were inhibited only by negatively charged sodium 2-(sulfonatoethyl) methane thiosulfonate (MTSES). In contrast, the I541C dimer remained insensitive to positive and negative reagents. However, I541C/D542G and I541C/D542N dimeric constructs were rapidly (