Effects of Nt-truncation and coexpression of isolated Nt domains on the membrane trafficking of electroneutral Na+/HCO3- cotransporters.
Effects of Nt-truncation and coexpression of isolated Nt domains on the membrane trafficking of electroneutral Na+/HCO3- cotransporters.
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Nt 截断和分离 Nt 结构域的共表达对电中性 Na /HCO3- 共转运蛋白膜运输的影响
DOI：
10.1038/srep12241
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发表时间：
2015-07-20
影响因子：
4.6
通讯作者：
Chen LM
中科院分区：
文献类型：
--
作者：
Wang DK;Liu Y;Myers EJ;Guo YM;Xie ZD;Jiang DZ;Li JM;Yang J;Liu M;Parker MD;Chen LM
SLC4基因均能够通过可变剪接或使用可变启动子产生多种变体。这种多样性所带来的生理影响引起了研究人员的浓厚兴趣。在此，我们鉴定出电中性钠/碳酸氢根共转运体NBCn1的两种新变体，一种是全长变体，起始于“MIPL”，另一种是N端截短变体，起始于“MDEL”。此外，我们还鉴定出编码NBCn2的Slc4a10的一个新启动子，以及一种新型的起始于“MHAN”的N端截短的NBCn2。当进行异源表达时，新的NBCn1变体能够很好地定位于质膜，并展现出典型的NBCn1活性。然而，MHAN - NBCn2在质膜上的定位较差。通过缺失突变，我们确定了对NBCn2表面定位至关重要的N端区域。有趣的是，共表达全长NBCn2可显著提高N端截短的NBCn2在细胞表面的丰度。免疫共沉淀和双分子荧光互补实验表明，全长和N端截短的NBCn2在Neuro - 2A细胞中相互作用形成异源二聚体。最后，我们发现分离出的N端结构域与N端截短的NBCn2相互作用，并提高其在细胞表面的丰度。本研究拓展了我们对NBCn1和NBCn2转录组的认识，并为了解N端结构域如何通过调节膜运输来影响转运体功能提供了新的视角。
The SLC4 genes are all capable of producing multiple variants by alternative splicing or using alternative promoters. The physiological consequences of such diversity are of great interest to investigators. Here, we identified two novel variants of the electroneutral Na+/ cotransporter NBCn1, one full-length starting with “MIPL” and the other Nt-truncated starting with “MDEL”. Moreover, we identified a new promoter of Slc4a10 encoding NBCn2 and a novel type of Nt-truncated NBCn2 starting with “MHAN”. When heterologously expressed, the new NBCn1 variants were well localized to the plasma membrane and exhibited characteristic NBCn1 activity. However, MHAN-NBCn2 was poorly localized on the plasma membrane. By deletion mutations, we identified the Nt regions important for the surface localization of NBCn2. Interestingly, coexpressing the full-length NBCn2 greatly enhances the surface abundance of the Nt-truncated NBCn2. Co-immunoprecipitation and bimolecular fluorescence complementation studies showed that the full-length and Nt-truncated NBCn2 interact with each other to form heterodimers in neuro-2A cells. Finally, we showed that the isolated Nt domain interacts with and enhances the surface abundance of the Nt-truncated NBCn2. The present study expands our knowledge of the NBCn1 and NBCn2 transcriptome, and provides insights into how the Nt domain could affect transporter function by regulating its membrane trafficking.
NBCn2 (Slc4a10) 剪接变体在小鼠大脑中的表达和分布：新变体 NBCn2-D 的克隆
影响因子：
2.9
作者：
Liu Y;Xu JY;Wang DK;Boron WF;Chen LM
通讯作者：
Chen LM