Trafficking and assembly of the cold-sensitive TRPM8 channel
Trafficking and assembly of the cold-sensitive TRPM8 channel
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DOI：
10.1074/jbc.m607756200
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发表时间：
2006-12-15
影响因子：
4.8
通讯作者：
Niemeyer, Barbara A.
中科院分区：
文献类型：
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作者：
Erler, Isabell;Al-Ansary, Dalia M. M.;Niemeyer, Barbara A.
TRPM（瞬时受体电位样melastatin）通道与瞬时受体电位家族的许多其他成员不同，其总体大小（约1000个氨基酸），缺乏n端锚蛋白样重复序列，以及可能允许超过6个跨膜区域的疏水性预测。每个TRPM成员共有一个突出的c端线圈区域。在这里，我们已经证明，TRPM8通道在细胞内C端使用假定的卷曲线圈区域作为多聚体组装，并且这种组装可以被卷曲线圈区域内的单点突变干扰。这种突变体既不产生功能通道，也不产生亚基相互作用或形成与多聚体相对应的蛋白质复合物。然而，它们仍然被运送到质膜。此外，野生型电流可以通过表达TRPM8的膜附着c端区来抑制。为了分离组装和运输，我们通过鉴定和突变相关的n链糖基化位点来研究TRPM8蛋白的成熟，结果表明糖基化对多聚和转运到质膜本身都不是必需的，但似乎促进了高效的多聚和转运。
TRPM( transient receptor potential melastatin-like) channels are distinct from many other members of the transient receptor potential family in regard to their overall size (> 1000 amino acids), the lack of N-terminal ankyrin-like repeats, and hydrophobicity predictions that may allow for more than six transmembrane regions. Common to each TRPM member is a prominent C-terminal coiled coil region. Here we have shown that TRPM8 channels assemble as multimers using the putative coiled coil region within the intracellular C terminus and that this assembly can be disturbed by a single point mutation within the coiled coil region. This mutant neither gives rise to functional channels nor do its subunits interact or form protein complexes that correspond to a multimer. However, they are still transported to the plasma membrane. Furthermore, wild-type currents can be suppressed by expressing the membrane-attached C-terminal region of TRPM8. To separate assembly from trafficking, we investigated the maturation of TRPM8 protein by identifying and mutating the relevant N-linked glycosylation site and showing that glycosylation is neither essential for multimerization nor for transport to the plasma membrane per se but appears to facilitate efficient multimerization and transport.