Constitutive high‐affinity choline transporter endocytosis is determined by a carboxyl‐terminal tail dileucine motif
Constitutive high‐affinity choline transporter endocytosis is determined by a carboxyl‐terminal tail dileucine motif
复制标题
组成型高亲和力胆碱转运蛋白内吞作用由羧基末端尾双亮氨酸基序决定
DOI：
--
复制
发表时间：
2005
影响因子：
4.7
通讯作者：
S. Ferguson
中科院分区：
文献类型：
--
作者：
F. Ribeiro;Stefanie A. G. Black;S. Cregan;V. Prado;Marco Antônio M. Prado;R. Rylett;S. Ferguson
乙酰胆碱合成的维持取决于高亲和力钠依赖性胆碱转运蛋白（CHT 1）的有效功能。最近的研究表明，这种转运蛋白主要定位于细胞内，不像其他神经递质转运蛋白，这表明CHT 1的运输和质膜可能在调节胆碱摄取中起着至关重要的作用。在这里，我们发现CHT 1在网格蛋白包被的囊泡中快速且组成性地内化为Rab 5阳性早期内体。CHT 1内化由非典型羧基末端双亮氨酸样基序（L531，V532）控制，其在被丙氨酸残基取代后，阻断CHT 1在人胚肾293细胞和原代皮质神经元中的内化，并导致CHT 1细胞表面表达和胆碱转运活性增加。用发动蛋白-I K44 A干扰网格蛋白介导的内吞作用增加了细胞表面表达和转运活性，其程度与突变双亮氨酸基序相似，这表明我们已经确定了负责组成性CHT 1内化的基序。基于观察到的本地化的CHT 1的质膜是短暂的，我们建议，乙酰胆碱的合成可能会受到影响的过程，导致衰减的组成CHT 1内吞。
Maintenance of acetylcholine synthesis depends on the effective functioning of a high‐affinity sodium‐dependent choline transporter (CHT1). Recent studies have shown that this transporter is predominantly localized inside the cell, unlike other neurotransmitter transporters, suggesting that the trafficking of CHT1 to and from the plasma membrane may play a crucial role in regulating choline uptake. Here we found that CHT1 is rapidly and constitutively internalized in clathrin‐coated vesicles to Rab5‐positive early endosomes. CHT1 internalization is controlled by an atypical carboxyl‐terminal dileucine‐like motif (L531, V532) which, upon replacement by alanine residues, blocks CHT1 internalization in both human embryonic kidney 293 cells and primary cortical neurons and results in both increased CHT1 cell surface expression and choline transport activity. Perturbation of clathrin‐mediated endocytosis with dynamin‐I K44A increases cell surface expression and transport activity to a similar extent as mutating the dileucine motif, suggesting that we have identified the motif responsible for constitutive CHT1 internalization. Based on the observation that the localization of CHT1 to the plasma membrane is transient, we propose that acetylcholine synthesis may be influenced by processes that lead to the attenuation of constitutive CHT1 endocytosis.
鲎 CNS 推定胆碱协同转运蛋白 cDNA 的分子克隆。
影响因子：
3.5
作者：
Wang,Y;Cao,Z;Newkirk,RF;Ivy,MT;Townsel,JG
通讯作者：
Townsel,JG
DOI：
10.1006/bbrc.2000.3561
发表时间：
2000-10-05
影响因子：
3.1
作者：
Apparsundaram, S;Ferguson, SM;Blakely, RD
通讯作者：
Blakely, RD