Localization of phosphatidylinositol phosphate kinase IIγ in kidney to a membrane trafficking compartment within specialized cells of the nephron
Localization of phosphatidylinositol phosphate kinase IIγ in kidney to a membrane trafficking compartment within specialized cells of the nephron
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DOI：
10.1152/ajprenal.90310.2008
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发表时间：
2008-11-01
影响因子：
4.2
通讯作者：
Irvine, Robin F.
中科院分区：
文献类型：
--
作者：
Clarke, Jonathan H.;Emson, Piers C.;Irvine, Robin F.
Clarke JH，Emson PC，Irvine RF.磷脂酰肌醇磷酸激酶II γ在肾脏中定位于肾单位特化细胞内的膜运输室。美国肾脏生理学杂志295：F1422-F1430，2008年。首次发表于2008年8月27日; doi：10.1152/ajprenal.90310.2008。- PIP 4K（II型磷脂酰肌醇4-磷酸激酶）是磷脂酰肌醇5-磷酸（PtdIns 5 P）4-激酶，据信主要调节细胞PtdIns 5 P水平。在这项研究中，我们研究了表达，定位，和相关的生物活性的研究最少的PIP 4K亚型，PIP 4K γ。定量RT-PCR和原位杂交显示，与PIP 4K α和PIP 4K β相比，PIP 4K γ在肾脏，特别是皮质和外髓质中以异常高的水平表达。一种特异性抗体被提高到PIP 4K γ，免疫组织化学与此和抗体特异性肾细胞标志物显示出有限的表达，主要分布在上皮细胞中的厚升支和集合管的闰细胞。在这些细胞中，PIP 4K γ具有囊泡外观，并且肾细胞系的转染揭示了部分高尔基体定位（主要是顺式高尔基体的基质），另外存在于未鉴定的囊泡隔室中。与PIP 4K α相反，细菌表达的重组PIP 4K γ是完全无活性的，但在体外确实具有与活性PIP 4K α缔合的能力。总体而言，我们的数据表明，PIP 4K γ可能在专门的肾上皮细胞中具有调节囊泡转运的功能。
Clarke JH, Emson PC, Irvine RF. Localization of phosphatidylinositol phosphate kinase II gamma in kidney to a membrane trafficking compartment within specialized cells of the nephron. Am J Physiol Renal Physiol 295: F1422-F1430, 2008. First published August 27, 2008; doi:10.1152/ajprenal.90310.2008.-PIP4Ks (type II phosphatidylinositol 4-phosphate kinases) are phosphatidylinositol 5-phosphate (PtdIns5P) 4-kinases, believed primarily to regulate cellular PtdIns5P levels. In this study, we investigated the expression, localization, and associated biological activity of the least-studied PIP4K isoform, PIP4K gamma. Quantitative RT-PCR and in situ hybridization revealed that compared with PIP4K alpha and PIP4K beta, PIP4K gamma is expressed at exceptionally high levels in the kidney, especially the cortex and outer medulla. A specific antibody was raised to PIP4K gamma, and immunohistochemistry with this and with antibodies to specific kidney cell markers showed a restricted expression, primarily distributed in epithelial cells in the thick ascending limb and in the intercalated cells of the collecting duct. In these cells, PIP4K gamma had a vesicular appearance, and transfection of kidney cell lines revealed a partial Golgi localization (primarily the matrix of the cis-Golgi) with an additional presence in an unidentified vesicular compartment. In contrast to PIP4K alpha, bacterially expressed recombinant PIP4K gamma was completely inactive but did have the ability to associate with active PIP4K alpha in vitro. Overall our data suggest that PIP4K gamma may have a function in the regulation of vesicular transport in specialized kidney epithelial cells.