Ito M, Inanobe A, Horio Y, Hibino H, Isomoto S, Ito H, Mori K, Tonosaki A, Tomoike H, Kurachi Y
Department of Cell Biology and Signaling, Yamagata University School of Medicine, Yamagata, Japan.
FEBS Lett. 1996 Jun 10;388(1):11-5. doi: 10.1016/0014-5793(96)00502-9.
Immunolocalization of K(AB)-2 (Kir4.1), an inwardly rectifying K+ channel with a putative ATP-binding domain, was examined in rat kidney where expression of K(AB)-2 mRNA was previously shown. Anti-K(AB)-2 antibody was raised in rabbit and then affinity-purified. An immunohistochemical study revealed that K(AB)-2 immunoreactivity was detected specifically in the basolateral membrane of distal tubular epithelia. Therefore, K(AB)-2 is the first K+ channel shown to be localized in the basolateral membrane of renal epithelia. The finding suggests that K(AB)-2 may contribute to supplying K+ to the Na(+)-K+ pump, which is abundant in the basolateral membrane of distal tubular epithelia, as well as to maintenance of the deep negative membrane potential of these cells.
在先前已显示K(AB)-2 mRNA表达的大鼠肾脏中，对一种带有假定ATP结合结构域的内向整流钾通道K(AB)-2（Kir4.1）进行了免疫定位研究。抗K(AB)-2抗体在兔体内产生，然后进行亲和纯化。一项免疫组织化学研究显示，K(AB)-2免疫反应性特异性地在远端肾小管上皮细胞的基底外侧膜中检测到。因此，K(AB)-2是首个被证明定位于肾上皮细胞基底外侧膜的钾通道。这一发现表明，K(AB)-2可能有助于向远端肾小管上皮细胞基底外侧膜中丰富的钠钾泵供应钾离子，以及维持这些细胞深部的负膜电位。
