Direct binding of visual arrestin to microtubules determines the differential subcellular localization of its splice variants in rod photoreceptors
Direct binding of visual arrestin to microtubules determines the differential subcellular localization of its splice variants in rod photoreceptors
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DOI：
10.1074/jbc.m406768200
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发表时间：
2004-09-24
影响因子：
4.8
通讯作者：
Slepak, VZ
中科院分区：
文献类型：
--
作者：
Nair, KS;Hanson, SM;Slepak, VZ
视觉抑制蛋白的正常功能对于杆状光感受器中信号的快速关闭是必不可少的。据信，其亚细胞定位的光依赖性显着变化在感光细胞的光适应中发挥着重要作用。在这里，我们展示了视觉抑制蛋白结合微管。视觉抑制蛋白 p44 的截短剪接变体对微管的亲和力明显高于全长蛋白 (p48)。 p44 增强的微管结合是其早期报道的优先定位于耐去污剂膜的基础，在该膜中，p44 通过膜相关微管以不依赖于视紫红质的方式锚定。纯化蛋白质的实验表明，视紫红质抑制蛋白与微管的相互作用是直接的，不需要任何额外的蛋白质伴侣。最重要的是，视紫红质抑制蛋白与微管和光激活磷酸化视紫红质的相互作用是相互排斥的，这表明微管相互作用可能在使 p44 视紫红质抑制蛋白远离暗适应光感受器中的视紫红质方面发挥作用。
Proper function of visual arrestin is indispensable for rapid signal shut-off in rod photoreceptors. Dramatic light dependent changes in its subcellular localization are believed to play an important role in light adaptation of photoreceptor cells. Here we show that visual arrestin binds microtubules. The truncated splice variant of visual arrestin, p44, demonstrates dramatically higher affinity for microtubules than the full-length protein (p48). Enhanced microtubule binding of p44 underlies its earlier reported preferential localization to detergent-resistant membranes, where it is anchored via membrane-associated microtubules in a rhodopsin-independent fashion. Experiments with purified proteins demonstrate that arrestin interaction with microtubules is direct and does not require any additional protein partners. Most importantly, arrestin interactions with microtubules and light-activated phosphorylated rhodopsin are mutually exclusive, suggesting that microtubule interaction may play a role in keeping p44 arrestin away from rhodopsin in dark-adapted photoreceptors.