The N-terminal basolateral targeting signal unlikely acts alone in the differential trafficking of membrane transporters in MDCK cells.
The N-terminal basolateral targeting signal unlikely acts alone in the differential trafficking of membrane transporters in MDCK cells.
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DOI：
10.1021/bi4005914
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发表时间：
2013-07-30
期刊：
影响因子：
2.9
通讯作者：
Blumenthal, Kenneth M.
中科院分区：
文献类型：
--
作者：
Kuo, Shiu-Ming;Wang, Li-Yuan;Yu, Siyuan;Campbell, Christine E.;Valiyaparambil, Sujith A.;Rance, Mark;Blumenthal, Kenneth M.
我们以前已经表明，使用共聚焦成像和运输分析，钠依赖性维生素C转运蛋白2（SVCT 2）的N-末端可以重定向顶端SVCT 1的基底外侧膜。在此，SVCT模型用于进一步表征基底外侧靶向肽信号。SVCT 2 N-末端的长度（31个氨基酸）和序列准确性在基底外侧靶向活性中很重要，表明了结构要求。然而，基于异源嵌合体的分析，N-末端基底外侧靶向序列似乎并不单独起作用。尽管来自多通道膜蛋白的不同N-末端基底外侧靶向信号都可以将来自相同基因家族的顶端蛋白重定向到基底外侧膜，但是没有一个N-末端基底外侧靶向信号可以将来自不同基因家族的TM和C-末端区域重定向。相反，这些异源N-末端基底外侧靶向信号的存在影响了其他顶端蛋白的运输，导致它们在稳定的微管蛋白样非肌动蛋白结构中积累。非靶向N-末端序列没有影响。当顶端或基底侧蛋白质的C-末端突变时，先前和本研究中观察到类似的蛋白质保留。这些结果表明，N末端和C末端在每个基因家族内直接或间接相互作用，以进行基底外侧靶向。CD和2D NMR分析均发现在保守的SVCT 2 N-末端缺乏规则的二级结构，与靶向单元中存在配偶体一致。我们的发现，从流行的单肽基序模型出发，是一致的基底侧转运蛋白从相应的顶端基因的演变。N-末端、其配偶体和细胞基底外侧靶向机制之间的相互作用需要进一步阐明。
We have shown previously, using confocal imaging and transport assays, that the N-terminus of the sodium-dependent vitamin C transporter 2 (SVCT2) can redirect apical SVCT1 to the basolateral membrane. Here, the SVCT model was used to further characterize the basolateral targeting peptide signal. Both the length (31 amino acids) and sequence accuracy of the SVCT2 N-terminus were found to be important in basolateral targeting activity, suggesting a structural requirement. However, the N-terminal basolateral targeting sequence did not appear to act alone, based on analyses of heterologous chimeras. Although diverse N-terminal basolateral targeting signals from multi-pass membrane proteins can all redirect apical protein from the same gene family to the basolateral membrane, none of the N-terminal basolateral targeting signals can redirect the TM and C-terminus regions from a different gene family. Instead, the presence of these heterologous N-terminal basolateral targeting signals affected the trafficking of otherwise apical protein, causing their accumulation in a stable tubulin-like non-actin structures. Non-targeting N-terminal sequences had no effect. Similar protein retention was observed previously and in this study when the C-terminus of apical or basolateral protein was mutated. These results suggest that the N- and C-termini interact, directly or indirectly, within each gene family for basolateral targeting. CD and 2D NMR analyses both found a lack of regular secondary structure in the conserved SVCT2 N-terminus, consistent with the presence of partner(s) in the targeting unit. Our finding, a departure from the prevailing single peptide motif model, is consistent with the evolution of basolateral transporters from the corresponding apical genes. The interaction among the N-terminus, its partner(s) and the cellular basolateral targeting machinery needs to be further elucidated.
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DOI：
10.1083/jcb.116.3.577
发表时间：
1992-02
期刊：
The Journal of cell biology
影响因子：
--
作者：
Mostov K;Apodaca G;Aroeti B;Okamoto C
通讯作者：
Okamoto C
影响因子：
2.9
作者：
Czachorowski, Maciej;Lam-Yuk-Tseung, Steven;Cellier, Mathieu;Gros, Philippe
通讯作者：
Gros, Philippe
影响因子：
2.7
作者：
DELAGLIO, F;GRZESIEK, S;BAX, A
通讯作者：
BAX, A
影响因子：
1.7
作者：
BRAUNSCHWEILER, L;BODENHAUSEN, G;ERNST, RR
通讯作者：
ERNST, RR
影响因子：
3.3
作者：
Quinones GB;Danowski BA;Devaraj A;Singh V;Ligon LA
通讯作者：
Ligon LA