A putative two pore channel AtTPC1 mediates Ca2+ flux in Arabidopsis leaf cells
A putative two pore channel AtTPC1 mediates Ca2+ flux in Arabidopsis leaf cells
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DOI：
10.1093/pcp/pce145
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发表时间：
2001-09-01
影响因子：
4.9
通讯作者：
Muto, S
中科院分区：
文献类型：
--
作者：
Furuichi, T;Cunningham, KW;Muto, S
目前尚未从植物中克隆到编码对Ca ~（2+）渗透具有高亲和力的电压门控通道的基因。在本研究中，我们分离了一个全长cDNA编码一个假定的钙离子通道（AtTPC 1）从拟南芥。AtTPC 1具有两个保守的同源结构域，每个结构域均含有6个跨膜片段（S1-S6）和一个位于S5和S6之间的孔环（P），与最近从大鼠中克隆的双孔通道TPC 1同源性最高。整体结构类似于动物电压激活Ca 2+通道α-亚基一般结构的一半。AtTPC 1拯救了酵母突变体cch 1的Ca 2+摄取活性。蔗糖诱导的发光，这反映了水母发光蛋白表达的拟南芥叶片胞质游离Ca 2+的增加，增强了过表达AtTPC 1和抑制它的反义表达。蔗糖-H+共转运体AtSUC 1和2，降低细胞膜电位接受蔗糖，也抑制了Ca 2+的增加，其反义表达。这些结果表明，AtTPC 1介导的电压激活的Ca 2+流入拟南芥叶细胞。
The gene encoding voltage-gated channel with high affinity for Ca2+ permeation has not been cloned from plants. In the present study, we isolated a full-length cDNA encoding a putative Ca2+ channel (AtTPC1) from Arabidopsis. AtTPC1 has two conserved homologous domains, both of which contain six transmembrane segments (S1-S6) and a pore loop (P) between S5 and S6 in each domain, and has the highest homology with the two pore channel TPC1 recently cloned from rat. The overall structure is similar to the half of the general structure of alpha -subunits of voltage-activated Ca2+ channels from animals. AtTPC1 rescued the Ca2+ uptake activity of a yeast mutant cch1. Sucrose-induced luminescence, which reflects a cytosolic free Ca2+ increase in aequorin-expressing Arabidopsis leaves, was enhanced by overexpression of AtTPC1 and suppressed by antisense expression of it. Sucrose-H+ symporters AtSUC1 and 2, which depolarize membrane potential of cells receiving sucrose, also depressed a Ca2+ increase by their antisense expression. These results suggest that AtTPC1 mediates a voltage-activated Ca2+ influx in Arabidopsis leaf cells.