Regulation of store-operated calcium entry by FK506-binding immunophilins
Regulation of store-operated calcium entry by FK506-binding immunophilins
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DOI：
10.1016/j.ceca.2012.12.008
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发表时间：
2013-04-01
期刊：
影响因子：
4
通讯作者：
Cioffi, Donna L.
中科院分区：
文献类型：
--
作者：
Kadeba, Pierre I.;Vasauskas, Audrey A.;Cioffi, Donna L.
钙离子从细胞外进入细胞是生理和病理生理功能中的重要信号传导机制。在非兴奋性细胞中，钙库操纵的钙（SOC）进入代表钙进入的主要模式。肺动脉内皮细胞中SOC进入的激活导致内皮细胞间间隙的形成和随后的内皮屏障破坏。对内皮SOC进入的调节知之甚少。在这项工作中，我们确定了两个大分子量的亲免素，FKBP 51和FKBP 52，作为新的调节SOC进入内皮细胞。FKBP 51和FKBP 52与SOC进入通道蛋白复合物的结合得到了亲免素与TRPC 4共沉淀的支持，TRPC 4是钙选择性通道的亚基，SOC进入通道I-SOC。地塞米松诱导的肺动脉内皮细胞FKBP 51表达上调减少了整体SOC进入以及I-SOC。当FKBP 51在诱导型HEK 293细胞系中过表达时，观察到类似的结果。另一方面，当FKBP 52过表达时，SOC进入增强。当FKBP 52的表达被抑制时，SOC进入减少。总的来说，我们的观察结果支持这些大分子量亲免素的调节作用，其中FKBP 51抑制内皮细胞中的SOC进入，而FKBP 52增强SOC进入。(c)2013爱思唯尔有限公司保留所有权利。
Calcium entry from the extracellular space into cells is an important signaling mechanism in both physiological and pathophysiological functions. In non-excitable cells, store-operated calcium (SOC) entry represents a principal mode of calcium entry. Activation of SOC entry in pulmonary artery endothelial cells leads to the formation of inter-endothelial cell gaps and subsequent endothelial barrier disruption. Regulation of endothelial SOC entry is poorly understood. In this work, we identify two large molecular weight immunophilins, FKBP51 and FKBP52, as novel regulators of SOC entry in endothelial cells. Using cell fractionation studies and immunocytochemistry we determined that a fraction of these largely cytosolic proteins localize to the plasma membrane where SOC entry channels are found. That FKBP51 and FKBP52 associate with SOC entry channel protein complexes was supported by co-precipitation of the immunophilins with TRPC4, a subunit of the calcium-selective, SOC entry channel I-SOC. Dexamethasone-induced upregulation of FKBP51 expression in pulmonary artery endothelial cells reduced global SOC entry as well as I-SOC. Similar results were observed when FKBP51 was over-expressed in an inducible HEK293 cell line. On the other hand, when FKBP52 was over-expressed SOC entry was enhanced. When expression of FKBP52 was inhibited, SOC entry was decreased. Collectively, our observations support regulatory roles for these large molecular weight immunophilins in which FKBP51 inhibits, whereas FKBP52 enhances, SOC entry in endothelial cells. (c) 2013 Elsevier Ltd. All rights reserved.