Biochemical and immunological characterization of renal protein kinase C.
Biochemical and immunological characterization of renal protein kinase C.
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肾蛋白激酶 C 的生化和免疫学特征。
DOI：
10.1152/ajprenal.1991.261.4.f679
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Jaken,S
中科院分区：
文献类型：
--
作者：
Dong,LQ;Stevens,JL;Jaken,S
蛋白激酶C （PKC）在肾脏转运和代谢功能调控中起重要作用。为了了解特定PKC同工酶在肾脏稳态中的作用，α -PKC的含量、调节和定位已经被表征。采用免疫吸附法测定大鼠肾PKC（以磷酯受体测量）中有34%为α -PKC。免疫组织化学染色α - pkc特异性单克隆抗体确定α - pkc存在于整个肾单位，特别是集中在近端小管和乳头状收集管。一般情况下，近端小管S3段比S1-S2段染色更强烈。皮质集管α - pkc染色差。乳头间质细胞也染色检测α - pkc。组织切片无法确定α - pkc的亚细胞分布；然而，在培养的近端小管上皮细胞中，α - pkc不仅定位于细胞质，还定位于细胞-细胞边界和局灶接触。大鼠肾可溶性部分的层析发现了两种内源性激酶抑制剂，一种是PKC特异性的，另一种是更一般的激酶抑制剂。PKC活性负调节因子的存在表明PKC的激活和失活对正常肾功能都很重要。
Protein kinase C (PKC) plays an important role in regulation of renal transport and metabolic function. To understand the role of a specific PKC isozyme in renal homeostasis, alpha-PKC content, regulation, and localization have been characterized. Immunoadsorption assays were used to determine that 34% of the total rat kidney PKC (measured as phorbol ester receptors) was alpha-PKC. Immunohistochemical staining with alpha-PKC-specific monoclonal antibodies determined that alpha-PKC was present throughout the nephron and was especially concentrated in proximal tubules and papillary collecting ducts. In general, the S3 segment of the proximal tubule stained more intensely than the S1-S2 segments. Cortical collecting ducts stained poorly for alpha-PKC. Interstitial cells of the papilla also stained for alpha-PKC. Subcellular distribution of alpha-PKC could not be determined in tissue sections; however, in cultured proximal tubule epithelial cells, alpha-PKC was localized not only in cytoplasm but also in cell-cell borders and focal contacts. Chromatography of rat kidney soluble fraction revealed two endogenous kinase inhibitors, one which is PKC specific and one which is a more general kinase inhibitor. The presence of negative regulators of PKC activity suggests that both activation and inactivation of PKC are important for normal renal function.