Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain.
Int J Mol Sci. 2019 Feb 9;20(3):734. doi: 10.3390/ijms20030734.
Ion channels are transmembrane proteins that conduct specific ions across biological membranes. Ion channels are present at the onset of many cellular processes, and their malfunction triggers severe pathologies. Potassium channels (KChs) share a highly conserved signature that is necessary to conduct K⁺ through the pore region. To be functional, KChs require an exquisite regulation of their subcellular location and abundance. A wide repertoire of signatures facilitates the proper targeting of the channel, fine-tuning the balance that determines traffic and location. These signature motifs can be part of the secondary or tertiary structure of the protein and are spread throughout the entire sequence. Furthermore, the association of the pore-forming subunits with different ancillary proteins forms functional complexes. These partners can modulate traffic and activity by adding their own signatures as well as by exposing or masking the existing ones. Post-translational modifications (PTMs) add a further dimension to traffic regulation. Therefore, the fate of a KCh is not fully dependent on a gene sequence but on the balance of many other factors regulating traffic. In this review, we assemble recent evidence contributing to our understanding of the spatial expression of KChs in mammalian cells. We compile specific signatures, PTMs, and associations that govern the destination of a functional channel.
离子通道是跨生物膜传导特定离子的跨膜蛋白。离子通道存在于许多细胞过程的开始，其功能障碍会引发严重的疾病。钾通道（KCh）具有高度保守的特征，是通过孔区传导 K⁺的必要条件。为了发挥功能，KCh 需要对其亚细胞位置和丰度进行精细调节。广泛的特征签名有助于正确靶向通道，微调决定流量和位置的平衡。这些特征基序可以是蛋白质二级或三级结构的一部分，并分布在整个序列中。此外，形成功能复合物的孔形成亚基与不同的辅助蛋白结合。这些伴侣可以通过添加自己的特征以及暴露或掩盖现有的特征来调节流量和活性。翻译后修饰（PTM）为流量调节增加了另一个维度。因此，KCh 的命运不完全取决于基因序列，而是取决于许多其他调节流量的因素的平衡。在这篇综述中，我们汇集了最近有助于我们理解哺乳动物细胞中 KCh 空间表达的证据。我们编译了控制功能性通道去向的特定特征、PTM 和关联。
