Binding of the GABA(A) receptor-associated protein (GABARAP) to microtubules and microfilaments suggests involvement of the cytoskeleton in GABARAPGABA(A) receptor interaction.
Binding of the GABA(A) receptor-associated protein (GABARAP) to microtubules and microfilaments suggests involvement of the cytoskeleton in GABARAPGABA(A) receptor interaction.
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发表时间：
2000
影响因子：
4.7
通讯作者：
H. Wang;R. Olsen
中科院分区：
文献类型：
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作者：
H. Wang;R. Olsen
GABA（A）受体相关蛋白（GABARAP）是根据其与GABA（A）受体γ 2亚基的相互作用而分离的。它与微管相关蛋白1A和1B的轻链3（LC 3）具有序列相似性。这表明GABARAP可能将GABA（A）受体连接到细胞骨架上。GABA在体外与微管蛋白结合。然而，关于相互作用的机制知之甚少，并且不清楚相互作用是否在体内发生。在这里，我们报告GABARAP直接与微管蛋白和微管在盐敏感的方式，表明协会介导的离子相互作用。GABARAP与微管蛋白共免疫沉淀，并与完整细胞中的微管和微丝结合。用紫杉醇、诺考达唑和细胞松弛素D处理改变细胞分布。微管蛋白结合结构域位于N端的GABARAP通过使用合成肽和缺失的构建体，并标记的碱性氨基酸的特定排列。GABARAP与肌动蛋白的相互作用可能是由其他蛋白介导的。这些结果表明GABARAP在体外和细胞中与细胞骨架相互作用，并提示GABARAP在GABA（A）受体与细胞骨架之间的相互作用中起作用。这种相互作用可能是受体运输、锚定和/或突触聚集所必需的。存在于GABARAP的微管蛋白结合结构域中的碱性氨基酸的结构排列可能有助于识别其他已知蛋白质中微管蛋白结合活性的潜力。
GABA(A) receptor-associated protein (GABARAP) was isolated on the basis of its interaction with the gamma2 subunit of GABA(A) receptors. It has sequence similarity to light chain 3 (LC3) of microtubule-associated proteins 1A and 1B. This suggests that GABARAP may link GABA(A) receptors to the cytoskeleton. GABARAP associates with tubulin in vitro. However, little is known about the mechanism for the interaction, and it is not clear whether the interaction occurs in vivo. Here, we report that GABARAP interacts directly with both tubulin and microtubules in a salt-sensitive manner, indicating the association is mediated by ionic interactions. GABARAP coimmunoprecipitates with tubulin and associates with both microtubules and microfilaments in intact cells. The cellular distribution is altered by treatment with taxol, nocodazole, and cytochalasin D. The tubulin binding domain was located at the N terminus of GABARAP by using synthetic peptides and deletion constructs and is marked by a specific arrangement of basic amino acids. The interaction between GABARAP and actin might be mediated by other proteins. These results demonstrate the GABARAP interacts with the cytoskeleton both in vitro and in cells and suggest a role of GABARAP in the interaction between GABA(A) receptors and the cytoskeleton. Such interactions are presumably needed for receptor trafficking, anchoring, and/or synaptic clustering. The structural arrangement of the basic amino acids present in the tubulin binding domain of GABARAP may aid in recognition of the potential of tubulin binding activity in other known proteins.