FODRIN-ANKYRIN CYTOSKELETON OF CHOROID-PLEXUS PREFERENTIALLY COLOCALIZES WITH APICAL NA+K+-ATPASE RATHER THAN WITH BASOLATERAL ANION-EXCHANGER AE2
FODRIN-ANKYRIN CYTOSKELETON OF CHOROID-PLEXUS PREFERENTIALLY COLOCALIZES WITH APICAL NA+K+-ATPASE RATHER THAN WITH BASOLATERAL ANION-EXCHANGER AE2
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DOI：
10.1172/jci117120
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发表时间：
1994-04-01
影响因子：
15.9
通讯作者：
DRENCKHAHN, D
中科院分区：
文献类型：
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作者：
ALPER, SL;STUARTTILLEY, A;DRENCKHAHN, D
作为单层上皮的脉络丛的一个独特特征是其顶端（内腔）表面的Na+K+-ATP酶的定位。与此相反，带3（AE 1）相关的阴离子交换蛋白已被定位到脉络丛的基底外侧表面。其他组织中的Na+K+-ATP酶和AE 1均通过锚蛋白结合到基于血影蛋白-肌动蛋白的膜细胞骨架上。由于连接的膜蛋白的膜细胞骨架是重要的，他们的限制专门的领域的细胞表面，我们调查的极性脉络丛膜细胞骨架。我们开发了同种型特异性抗体来确认脉络丛带3相关多肽的身份为AE 2。我们证明，锚蛋白，胞衬蛋白/血影蛋白，肌动蛋白，肌球蛋白，和cr-actinin主要是在脉络丛顶端，并优先与顶端Na+K+-ATP酶，而不是与基底外侧阴离子交换AE 2共定位。秋水仙碱管理没有改变脉络丛顶端细胞骨架和转运蛋白或基底外侧AE 2的极性，这表明这些蛋白质的生物合成靶向不是微管依赖性的。脉络丛乳头状瘤Na+-K+-ATP酶和AE 2含量减少，不能维持其极化分布。
A unique feature of the choroid plexus as a single-layer epithelium is its localization of Na+K+-ATPase at its apical (lumenal) surface. In contrast, a band 3 (AE1)-related anion exchanger protein has been localized to the basolateral surface of the choroid plexus. Both Na+K+-ATPase and AE1 in other tissues have been shown to bind via ankyrin to the spectrin-actin-based membrane cytoskeleton. Since linkage of integral membrane proteins to the membrane cytoskeleton is important for their restriction to specialized domains of the cell surface, we investigated the polarity of the choroid plexus membrane cytoskeleton. We developed isoform-specific antibodies to confirm the identity of choroid plexus band 3-related polypeptide as AE2. We demonstrated that ankyrin, fodrin/spectrin, actin, myosin, and cr-actinin are predominantly apical in choroid plexus and preferentially colocalize with apical Na+K+-ATPase rather than with basolateral anion exchanger AE2. Colchicine administration did not alter the polarity of apical cytoskeletal and transport proteins or basolateral AE2 in choroid plexus, suggesting that biosynthetic targeting of these proteins is not microtubule dependent. In choroid plexus papilloma, Na+K+-ATPase and AE2 were decreased in amount and failed to preserve their polarized distributions.