EFA6A, a gunanine nucleotide exchange factor for Arf6, interacts with sorting nexin-1 and regulates neurite outgrowth
EFA6A, a gunanine nucleotide exchange factor for Arf6, interacts with sorting nexin-1 and regulates neurite outgrowth
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EFA6A 是 Arf6 的鸟嘌呤核苷酸交换因子，与分选 nexin-1 相互作用并调节神经突生长
DOI：
10.1111/jnc.12524
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Sakagami H
中科院分区：
文献类型：
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作者：
Fukaya M;Fukushima D;Hara Y;Sakagami H
由ADP核糖基化因子6（Arf 6）介导的膜运输和肌动蛋白细胞骨架重塑在功能上与各种神经过程相关，包括轴突形成和维持、神经递质释放和受体内化。EFA 6A是一种Arf 6特异性鸟嘌呤核苷酸交换因子，在大脑中大量表达。在这项研究中，我们通过酵母双杂交筛选确定了分选连接蛋白-1（SNX 1），一种参与内体分选和运输的逆转录组分，作为EFA 6A的新型相互作用伴侣。这种相互作用是由EFA 6A的C末端区域和SNX 1的BAR结构域介导的，并通过拉下试验和小鼠脑裂解物的免疫沉淀进一步证实。原位杂交分析表明SNX 1在小鼠脑中广泛表达，这与EFA 6A在前脑中的表达重叠。免疫荧光分析显示EFA 6A和SNX 1在海马树突状区域的部分共定位。免疫电镜分析显示EFA 6A和SNX 1在树突棘中突触后密度和内体的重叠亚细胞定位。在Neuro-2a神经母细胞瘤细胞中，EFA 6A或SNX 1的表达诱导神经突生长，EFA 6A和SNX 1的共表达进一步增强了神经突生长。本研究结果提示EFA 6A通过与SNX 1相互作用调控Arf 6介导的神经突形成的一种新机制。我们鉴定了分选连接蛋白-1（SNX 1）作为EFA 6A的一种新的结合伴侣，并证实了EFA 6A和SNX 1在海马神经元棘和树突中的重叠超微结构定位。此外，我们发现这种相互作用增强了Neuro-2a细胞的神经突生长。目前的研究结果表明EFA 6A和SNX 1之间的相互作用在Arf 6介导的树突棘神经元功能中的重要性。
The membrane trafficking and actin cytoskeleton remodeling mediated by ADP ribosylation factor 6 (Arf6) are functionally linked to various neuronal processes including neurite formation and maintenance, neurotransmitter release, and receptor internalization. EFA6A is an Arf6‐specific guanine nucleotide exchange factor that is abundantly expressed in the brain. In this study, we identified sorting nexin‐1 (SNX1), a retromer component that is implicated in endosomal sorting and trafficking, as a novel interacting partner for EFA6A by yeast two‐hybrid screening. The interaction was mediated by the C‐terminal region of EFA6A and a BAR domain of SNX1, and further confirmed by pull‐down assay and immunoprecipitation from mouse brain lysates.In situhybridization analysis demonstrated the widespread expression of SNX1 in the mouse brain, which overlapped with the expression of EFA6A in the forebrain. Immunofluorescent analysis revealed the partial colocalization of EFA6A and SNX1 in the dendritic fields of the hippocampus. Immunoelectron microscopic analysis revealed the overlapping subcellular localization of EFA6A and SNX1 at the post‐synaptic density and endosomes in dendritic spines. In Neuro‐2a neuroblastoma cells, expression of either EFA6A or SNX1 induced neurite outgrowth, which was further enhanced by co‐expression of EFA6A and SNX1. The present findings suggest a novel mechanism by which EFA6A regulates Arf6‐mediated neurite formation through the interaction with SNX1.We identified sorting nexin‐1 (SNX1) as a novel binding partner for EFA6A, and demonstrated overlapping ultrastructural localization of EFA6A and SNX1 in spines and dendrites of hippocampal neurons. Furthermore, we showed that this interaction enhanced neurite outgrowth of Neuro‐2a cells. The present findings suggest the importance of the interaction between EFA6A and SNX1 in Arf6‐mediated neuronal functions in dendritic spines.