Annexin II light chain p11 promotes functional expression of acid-sensing ion channel ASIC1a
Annexin II light chain p11 promotes functional expression of acid-sensing ion channel ASIC1a
复制标题
DOI：
10.1074/jbc.m505981200
复制
发表时间：
2005-11-18
影响因子：
4.8
通讯作者：
Wood, JN
中科院分区：
文献类型：
--
作者：
Donier, E;Rugiero, F;Wood, JN
酸敏感离子通道（ASIC）参与了多种生理功能。我们已经使用了大鼠背根神经节cDNA文库中的酵母双杂交试验，以确定与ASIC相互作用的感觉神经元蛋白。我们发现膜联蛋白II轻链p11与ASIC 1a的N末端发生物理相互作用，但不与其他ASIC亚型发生相互作用。免疫沉淀研究证实了p11和ASIC 1在大鼠背根神经节神经元在体内的相互作用。CHO-K1细胞中p11和ASIC 1a的共表达导致细胞膜上离子通道的表达增加2倍，这通过膜相关免疫反应性和细胞表面生物素化来确定。与这些发现一致，在转染CHO-K1细胞的峰值ASIC 1a电流在p11存在下上调2倍，而ASIC 3介导的电流不受p11表达的影响。p11既不改变激活的pH依赖性，也不改变脱敏的速率，这表明其在调节ASIC 1a活性中的主要作用是增强ASIC 1a的细胞表面表达。这些数据表明，p11，已经知道交通成员的电压门控钠和钾通道家族以及瞬时受体电位和氯离子通道，也发挥了选择性的作用，在增强ASIC 1a功能表达。
Acid-sensing ion channels (ASICs) have been implicated in a wide variety of physiological functions. We have used a rat dorsal root ganglion cDNA library in a yeast two-hybrid assay to identify sensory neuron proteins that interact with ASICs. We found that annexin II light chain p11 physically interacts with the N terminus of ASIC1a, but not other ASIC isoforms. Immunoprecipitation studies confirmed an interaction between p11 and ASIC1 in rat dorsal root ganglion neurons in vivo. Coexpression of p11 and ASIC1a in CHO-K1 cells led to a 2-fold increase in expression of the ion channel at the cell membrane as determined by membrane-associated immunoreactivity and cell-surface biotinylation. Consistent with these findings, peak ASIC1a currents in transfected CHO-K1 cells were up-regulated 2-fold in the presence of p11, whereas ASIC3-mediated currents were unaffected by p11 expression. Neither the pH dependence of activation nor the rates of desensitization were altered by p11, suggesting that its primary role in regulating ASIC1a activity is to enhance cell-surface expression of ASIC1a. These data demonstrate that p11, already known to traffic members of the voltage-gated sodium and potassium channel families as well as transient receptor potential and chloride channels, also plays a selective role in enhancing ASIC1a functional expression.