Pannexin2 oligomers localize in the membranes of endosomal vesicles in mammalian cells while Pannexin1 channels traffic to the plasma membrane.
Pannexin2 oligomers localize in the membranes of endosomal vesicles in mammalian cells while Pannexin1 channels traffic to the plasma membrane.
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DOI：
10.3389/fncel.2014.00468
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发表时间：
2014
影响因子：
5.3
通讯作者：
Sosinsky GE
中科院分区：
文献类型：
--
作者：
Boassa D;Nguyen P;Hu J;Ellisman MH;Sosinsky GE
Pannexin2 （Panx2）是pannexin蛋白的三个成员中最大的一个。泛连接蛋白在拓扑结构上与连接蛋白和内连接蛋白相关，但与形成间隙连接相比具有不同的功能作用。我们之前表明，泛连接蛋白形成寡聚通道，但与连接蛋白和内连接蛋白不同，它们只形成单一的膜通道。高水平的Panx2 mRNA和蛋白在中枢神经系统（CNS）已被证实。Pannexin1 （Panx1）普遍存在，Pannexin3 （Panx3）存在于皮肤和结缔组织中，两者都被完全糖基化，运输到质膜，并具有与细胞外ATP释放相关的功能。在这里，我们描述了MDCK、HeLa和HEK 293T细胞中外源性Panx2和Panx1蛋白表达的转运和亚细胞定位，以及内源性Panx1和Panx2在中枢神经系统中的表达模式。Panx2在细胞内定位，部分n-糖基化，定位与Panx1不重叠。星形胶质细胞蛋白GFAP、Panx1和Panx2免疫标记的海马切片共聚焦图像表明，Panx1和Panx2两种同工异构体定位于星形胶质细胞和神经元的不同亚细胞区室。利用在相关光镜和电镜下开发的带有附加遗传标签的重组Panx2融合体，然后在不同细胞系中表达，我们确定Panx2定位于细胞内囊泡膜，而不是像钙连蛋白共定位实验最初显示的那样定位于内质网。特异囊泡室蛋白标记的双重免疫荧光成像显示Panx2囊泡起源于早期的内体。在电子层析体积中，这些囊泡的横截面显示出精细的结构细节和与肌动蛋白丝的密切接近。因此，在不同亚细胞区室表达的泛联蛋白可能发挥不同的功能作用，特别是在神经系统中。
Pannexin2 (Panx2) is the largest of three members of the pannexin proteins. Pannexins are topologically related to connexins and innexins, but serve different functional roles than forming gap junctions. We previously showed that pannexins form oligomeric channels but unlike connexins and innexins, they form only single membrane channels. High levels of Panx2 mRNA and protein in the Central Nervous System (CNS) have been documented. Whereas Pannexin1 (Panx1) is fairly ubiquitous and Pannexin3 (Panx3) is found in skin and connective tissue, both are fully glycosylated, traffic to the plasma membrane and have functions correlated with extracellular ATP release. Here, we describe trafficking and subcellular localizations of exogenous Panx2 and Panx1 protein expression in MDCK, HeLa, and HEK 293T cells as well as endogenous Panx1 and Panx2 patterns in the CNS. Panx2 was found in intracellular localizations, was partially N-glycosylated, and localizations were non-overlapping with Panx1. Confocal images of hippocampal sections immunolabeled for the astrocytic protein GFAP, Panx1 and Panx2 demonstrated that the two isoforms, Panx1 and Panx2, localized at different subcellular compartments in both astrocytes and neurons. Using recombinant fusions of Panx2 with appended genetic tags developed for correlated light and electron microscopy and then expressed in different cell lines, we determined that Panx2 is localized in the membrane of intracellular vesicles and not in the endoplasmic reticulum as initially indicated by calnexin colocalization experiments. Dual immunofluorescence imaging with protein markers for specific vesicle compartments showed that Panx2 vesicles are early endosomal in origin. In electron tomographic volumes, cross-sections of these vesicles displayed fine structural details and close proximity to actin filaments. Thus, pannexins expressed at different subcellular compartments likely exert distinct functional roles, particularly in the nervous system.
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影响因子：
1.7
作者：
Burns, Alan R.;Phillips, Sharon C.;Sokoya, Elke M.
通讯作者：
Sokoya, Elke M.
影响因子：
7.2
作者：
Gautreau, Alexis;Oguievetskaia, Ksenia;Ungermann, Christian
通讯作者：
Ungermann, Christian
DOI：
10.1097/00005072-199908000-00010
发表时间：
1999-08-01
影响因子：
3.2
作者：
Ino, Y;Silver, JS;Louis, DN
通讯作者：
Louis, DN
DOI：
10.1073/pnas.2233464100
发表时间：
2003-11-11
影响因子：
11.1
作者：
Bruzzone, R;Hormuzdi, SG;Monyer, H
通讯作者：
Monyer, H
影响因子：
5.3
作者：
Bushong, EA;Martone, ME;Ellisman, MH
通讯作者：
Ellisman, MH