Lurin C, Geelen D, Barbier-Brygoo H, Guern J, Maurel C
Institut des Sciences Végétales, Centre National de la Recherche Scientifique (CNRS), Gif sur Yvette, France.
Plant Cell. 1996 Apr;8(4):701-11. doi: 10.1105/tpc.8.4.701.
Plant cell membrane anion channels participate in basic physiological functions, such as cell volume regulation and signal transduction. However, nothing is known about their molecular structure. Using a polymerase chain reaction strategy, we have cloned a tobacco cDNA (CIC-Nt1) encoding a 780-amino acid protein with several putative transmembrane domains. CIC-Nt1 displays 24 to 32% amino acid identity with members of the animal voltage-dependent chloride channel (CIC) family, whose archetype is CIC-0 from the Torpedo marmorata electric organ. Injection of CIC-Nt1 complementary RNA into Xenopus oocytes elicited slowly activating inward currents upon membrane hyperpolarization more negative than -120 mV. These currents were carried mainly by anions, modulated by extracellular anions, and totally blocked by 10 mM extracellular calcium. The identification of CIC-Nt1 extends the CIC family to higher plants and provides a molecular probe for the study of voltage-dependent anion channels in plants.
植物细胞膜阴离子通道参与细胞体积调节和信号转导等基本生理功能。然而，其分子结构尚不清楚。我们采用聚合酶链反应策略，克隆了一个烟草cDNA（CIC-Nt1），它编码一个含有几个推定跨膜结构域的780个氨基酸的蛋白质。CIC-Nt1与动物电压依赖性氯离子通道（CIC）家族成员的氨基酸同一性为24%至32%，该家族的原型是来自电鳐电器官的CIC-0。将CIC-Nt1互补RNA注射到非洲爪蟾卵母细胞中，当膜超极化至比-120 mV更负时，会引发缓慢激活的内向电流。这些电流主要由阴离子携带，受细胞外阴离子调节，并被10 mM细胞外钙完全阻断。CIC-Nt1的鉴定将CIC家族扩展到高等植物，并为研究植物中的电压依赖性阴离子通道提供了分子探针。
