Identification of EFHD1 as a novel Ca2+ sensor for mitoflash activation
Identification of EFHD1 as a novel Ca2+ sensor for mitoflash activation
复制标题
鉴定 EFHD1 作为一种用于线粒体闪激活的新型 Ca2 传感器
DOI：
10.1016/j.ceca.2016.03.002
复制
发表时间：
2016-05-01
期刊：
影响因子：
4
通讯作者：
Wang, Xianhua
中科院分区：
文献类型：
--
作者：
Hou, Tingting;Jian, Chongshu;Wang, Xianhua
Mitochondrial flashes (mitoflashes) represent stochastic and discrete mitochondrial events that each comprises a burst of superoxide production accompanied by transient depolarization and matrix alkalinization in a respiratory mitochondrion. While mitochondrial Ca2+ is shown to be an important regulator of mitoflash activity, little is known about its specific mechanism of action. Here we sought to determine possible molecular players that mediate the Ca2+ regulation of mitoflashes by screening mitochondrial proteins containing the Ca2+-binding motifs. In silico analysis and targeted siRNA screening identified four mitoflash, activators (MICUI, EFHDI, SLC25A23, SLC25A25) and one mitoflash inhibitor (LETM1) in terms of their ability to modulate mitoflash response to hyperosmotic stress. In particular, overexpression or down-regulation of EFHD1 enhanced or depressed mitoflash activation, respectively, under various conditions of mitochondrial Ca2+ elevations. Yet, it did not alter mitochondrial Ca2+ handling, mitochondrial respiration, or ROS-induced mitoflash production. Further, disruption of the two EF-hand motifs of EFHD1 abolished its potentiating effect on the mitoflash responses. These results indicate that EFHD1 functions as a novel mitochondrial Ca2+ sensor underlying Ca2+-dependent activation of mitoflashes. (C) 2016 Elsevier Ltd. All rights reserved.
