The C-terminus is critical for the functional expression of the human serotonin transporter
The C-terminus is critical for the functional expression of the human serotonin transporter
复制标题
DOI：
10.1021/bi0508688
复制
发表时间：
2006-01-31
期刊：
影响因子：
2.9
通讯作者：
Wiborg, O
中科院分区：
文献类型：
--
作者：
Larsen, MB;Fjorback, AW;Wiborg, O
细胞膜上的雌激素转运体（SERT）通过从突触间隙重摄取5-HT，在终止多巴胺能神经传递中起重要作用。因此，SERT在细胞表面的表达是一个关键因素。在这项研究中，我们研究了在运输到质膜的SERT的羧基末端的作用。5-HT摄取活性用于测量C-末端系统性缺失或丙氨酸取代的影响。我们发现，在远端C-末端的16个氨基酸的缺失对摄取活性没有影响，而进一步的缺失对SERT的功能是有害的。使用细胞表面生物素化来确定C-末端在定位和运输中的作用。我们表明，C-末端是至关重要的SERT的质膜和运输的这一部分的缺失导致缺乏成熟的糖基化和受损的运输到质膜。此外，C-末端截短的突变体显示出对野生型SERT摄取活性具有显性负效应。
The plasma membrane scrotonin transporter (SERT) has an important role in terminating serotonergic neurotransmission by re-uptake of 5-HT from the synaptic cleft. The expression of SERT on the cell surface is therefore a critical factor. In this study, we examined the role of the carboxyl terminus of SERT in trafficking to the plasma membrane. 5-HT uptake activity was used to measure the effects of systematic deletions or alanine substitutions in the C-terminus. We found that deletion of 16 amino acids in the distal C-terminus had no effect on uptake activity, whereas further deletion was detrimental for the function of SERT. Cell surface biotinylation was used to determine the role of the C-terminus in localization and trafficking. We showed that the C-terminus is crucial for the delivery of SERT to the plasma membrane and that the deletion of this part of the transporter results in a lack of mature glycosylation and impaired trafficking to the plasma membrane. Furthermore, the C-terminally truncated mutants were shown to have a dominant negative effect on wild-type SERT uptake activity.