IMMUNOLOCALIZATION OF THE MERCURIAL-INSENSITIVE WATER CHANNEL AND GLYCEROL INTRINSIC PROTEIN IN EPITHELIAL-CELL PLASMA-MEMBRANES
IMMUNOLOCALIZATION OF THE MERCURIAL-INSENSITIVE WATER CHANNEL AND GLYCEROL INTRINSIC PROTEIN IN EPITHELIAL-CELL PLASMA-MEMBRANES
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DOI：
10.1073/pnas.92.10.4328
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发表时间：
1995-05-09
影响因子：
11.1
通讯作者：
VERKMAN, AS
中科院分区：
文献类型：
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作者：
FRIGERI, A;GROPPER, MA;VERKMAN, AS
最近从大鼠肾脏中克隆了两个水通道同源物，分别是汞不敏感水通道（MIWC）和甘油内在蛋白（GLIP）。制备了针对合成的c端肽的多克隆抗体，并通过亲和层析纯化。MIWC和CLIP抗体分别识别大鼠肾脏中表观分子质量为30和27 kDa的蛋白，且不发生交叉反应，免疫荧光检测显示MIWC和GLIP在肾收集管主细胞基底外侧质膜上同时表达，免疫组织化学检测显示MIWC和GLIP在气管上皮细胞上表达，其中GLIP在基底质膜和Mn上表达较多；侧膜上的VC；在眼睛中，GLIP在结膜上皮中表达，而在虹膜、睫状体和视网膜的神经细胞层中发现了MIWC， MIWC和GLIP在结肠和脑室管膜细胞的绒毛上皮的基底外膜上共定位，在小肠、肝脏、脾脏、内皮和表达水通道CHIP28或WCH-CD的细胞中未检测到MIWC和GLIP的表达。这些研究表明，MIWC和GLIP在尿浓缩机制、脑脊液吸收、眼液平衡、粪便脱水和气道湿化等方面具有水/溶质转运作用。MIWC和GLIP在几个组织中意想不到的膜共定位表明在分子和/或功能水平上存在相互作用。
Two water channel homologs were cloned recently from rat kidney, mercurial-insensitive water channel (MIWC) and glycerol intrinsic protein (GLIP). Polyclonal antibodies were raised against synthetic C-terminal peptides and purified by affinity chromatography. MIWC and CLIP antibodies recognized proteins in rat kidney with an apparent molecular mass of 30 and 27 kDa, respectively, and did not cross-react, By immunofluorescence, MIWC and GLIP were expressed together on the basolateral plasma membrane of collecting duct principal cells in kidney, By immunohistochemistry, MIWC and GLIP were expressed on tracheal epithelial cells with greater expression of GLIP on the basal plasma membrane and Mn;VC on the lateral membrane; only MIWC was expressed in bronchial epithelia, In eye, GLIP was expressed in conjunctival epithelium, whereas MIWC was found in iris, ciliary body, and neural cell layers in retina, MIWC and GLIP colocalized on the basolateral membrane of villus epithelial cells in colon and brain ependymal cells, Expression of MIWC and GLIP was not detected in small intestine, liver, spleen, endothelia, and cells that express water channels CHIP28 or WCH-CD, These studies suggest water/solute transporting roles for MIWC and GLIP in the urinary concentrating mechanism, cerebrospinal fluid absorption, ocular fluid balance, fecal dehydration, and airway humidification. The unexpected membrane colocalization of MIWC and GLIP in several tissues suggests an interaction at the molecular and/or functional levels.