Calcyon, a novel partner of clathrin light chain, stimulates clathrin-mediated endocytosis.
Calcyon, a novel partner of clathrin light chain, stimulates clathrin-mediated endocytosis.
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Calcyon 是网格蛋白轻链的新型伙伴，可刺激网格蛋白介导的内吞作用。
DOI：
10.1074/jbc.m600265200
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Bergson,Clare
中科院分区：
文献类型：
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作者：
Xiao,Jiping;Dai,Rujuan;Negyessy,Laszlo;Bergson,Clare
在中枢神经系统中，网格蛋白介导的内吞作用对于有效的突触传递至关重要。网格蛋白包被的囊泡的组装和拆卸由大约30种衔接蛋白和辅助蛋白调节，其中大多数与网格蛋白重链相互作用。利用钙蛋白胞质结构域作为诱饵，我们在酵母双杂交筛选中分离网格蛋白轻链。将相互作用结构域定位到重链结合结构域和轻链的C-末端区域。此外，钙蛋白C末端的加入以剂量依赖性方式刺激网格蛋白自组装。钙蛋白是一种主要在脑内表达的单跨膜蛋白，定位于突触前和突触后结构内的囊泡区室。LC和钙蛋白在神经元树突、棘和胞体中的分布高度重叠。免疫共沉淀研究进一步表明钙蛋白与网格蛋白介导的内吞机制相关。与对照组相比，过表达钙蛋白的HEK 293细胞表现出显着增强的转铁蛋白摄取，但回收水平相当。相反，从钙蛋白缺失等位基因纯合小鼠中获得的新皮质神经元中转铁蛋白的吸收在很大程度上被消除，而回收在野生型水平上进行。总的来说，这些数据表明钙蛋白在网格蛋白介导的脑内吞作用中的作用。
In the central nervous system, clathrin-mediated endocytosis is crucial for efficient synaptic transmission. Clathrin-coated vesicle assembly and disassembly is regulated by some 30 adaptor and accessory proteins, most of which interact with clathrin heavy chain. Using the calcyon cytosolic domain as bait, we isolated clathrin light chain in a yeast two-hybrid screen. The interaction domain was mapped to the heavy chain binding domain and C-terminal regions of light chain. Further, the addition of the calcyon C terminus stimulated clathrin self-assembly in a dose-dependent fashion. Calcyon, which is a single transmembrane protein predominantly expressed in brain, localized to vesicular compartments within pre- and postsynaptic structures. There was a high degree of overlap in the distribution of LC and calcyon in neuronal dendrites, spines, and cell bodies. Co-immunoprecipitation studies further suggested an association of calcyon with the clathrin-mediated endocytic machinery. Compared with controls, HEK293 cells overexpressing calcyon exhibited significantly enhanced transferrin uptake but equivalent levels of recycling. Conversely, transferrin uptake was largely abolished in neocortical neurons obtained from mice homozygous for a calcyon null allele, whereas recycling proceeded at wild type levels. Collectively, these data indicate a role for calcyon in clathrin-mediated endocytosis in brain.