Caspr2, a new member of the neurexin superfamily, is localized at the juxtaparanodes of myelinated axons and associates with K+ channels
Caspr2, a new member of the neurexin superfamily, is localized at the juxtaparanodes of myelinated axons and associates with K+ channels
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DOI：
10.1016/s0896-6273(00)81049-1
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发表时间：
1999-12-01
期刊：
影响因子：
16.2
通讯作者：
Peles, E
中科院分区：
文献类型：
--
作者：
Poliak, S;Gollan, L;Peles, E
有髓轴突的快速传导依赖于特定亚细胞结构域的产生，不同的离子通道定位于这些亚细胞结构域。在这里，我们描述的识别Caspr 2，哺乳动物同源的果蝇Neurexin IV（NRX-IV），并表明，这种neurexin样蛋白和密切相关的分子Caspr/Paranodin划定不同的亚结构域在有髓轴突。虽然接触素相关蛋白（Caspr）存在于结旁连接处，但Caspr 2精确地与Shaker样K+通道共定位于结旁区域。我们进一步表明，Caspr 2特异性地与Kv1.1，Kv1.2及其Kv β 2亚基相关。这种关联涉及Caspr 2的C-末端序列，其含有推定的PDZ结合位点。这些结果表明，在局部分化的轴突成不同的功能子域的Caspr家族成员的作用。
Rapid conduction in myelinated axons depends on the generation of specialized subcellular domains to which different sets of ion channels are localized. Here, we describe the identification of Caspr2, a mammalian homolog of Drosophila Neurexin IV (Nrx-IV), and show that this neurexin-like protein and the closely related molecule Caspr/Paranodin demarcate distinct subdomains in myelinated axons. While contactin-associated protein (Caspr) is present at the paranodal junctions, Caspr2 is precisely colocalized with Shaker-like K+ channels in the juxtaparanodal region. We further show that Caspr2 specifically associates with Kv1.1, Kv1.2, and their Kv beta 2 subunit. This association involves the C-terminal sequence of Caspr2, which contains a putative PDZ binding site. These results suggest a role for Caspr family members in the local differentiation of the axon into distinct functional subdomains.