Targeted siRNA Screens Identify ER-to-Mitochondrial Calcium Exchange in Autophagy and Mitophagy Responses in RPE1 Cells.
Targeted siRNA Screens Identify ER-to-Mitochondrial Calcium Exchange in Autophagy and Mitophagy Responses in RPE1 Cells.
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DOI：
10.3390/ijms160613356
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发表时间：
2015-06-11
影响因子：
5.6
通讯作者：
Lane JD
中科院分区：
文献类型：
--
作者：
MacVicar TD;Mannack LV;Lees RM;Lane JD
自噬是一种重要的应激反应途径，负责清除和回收受损或多余的胞浆成分。线粒体损伤触发选择性线粒体自噬(有丝分裂吞噬)，由包括PINK1/Parkin系统在内的多种反应因子介导。利用稳定表达自噬和有丝分裂吞噬的人视网膜色素上皮细胞，我们对与饥饿诱导的自噬和损伤诱导的有丝分裂吞噬有关的内质网(ER)调节因子和线粒体的形态和功能进行了平行筛选。这些筛选确定内质网伴侣和钙离子流量调节器，SIGMAR1，非阿片样胞内受体1(SIGMAR1)，在饥饿期间调节自噬小体的扩张。筛查还发现磷脂酰乙醇胺甲基转移酶(PEMT)和IP3受体(IP3Rs)是Parkin诱导有丝分裂吞噬的媒介。进一步的实验表明，IP3R通过线粒体钙离子单一转运体(MCU)介导的钙离子从内质网腔向线粒体基质的转移启动了线粒体的有丝分裂。重要的是，Parkin募集到受损的线粒体不需要IP3R介导的内质网到线粒体的钙转移，但Parkin募集下游的线粒体聚集受到损害，这表明线粒体动力学和/或运输调节因子的参与。我们的数据表明，无论是饥饿诱导的自噬还是Parkin介导的有丝分裂吞噬，都需要内质网和线粒体之间的钙通量，这进一步强调了细胞器间通讯对有效的细胞动态平衡的重要性。
Autophagy is an important stress response pathway responsible for the removal and recycling of damaged or redundant cytosolic constituents. Mitochondrial damage triggers selective mitochondrial autophagy (mitophagy), mediated by a variety of response factors including the Pink1/Parkin system. Using human retinal pigment epithelial cells stably expressing autophagy and mitophagy reporters, we have conducted parallel screens of regulators of endoplasmic reticulum (ER) and mitochondrial morphology and function contributing to starvation-induced autophagy and damage-induced mitophagy. These screens identified the ER chaperone and Ca2+ flux modulator, sigma non-opioid intracellular receptor 1 (SIGMAR1), as a regulator of autophagosome expansion during starvation. Screens also identified phosphatidyl ethanolamine methyl transferase (PEMT) and the IP3-receptors (IP3Rs) as mediators of Parkin-induced mitophagy. Further experiments suggested that IP3R-mediated transfer of Ca2+ from the ER lumen to the mitochondrial matrix via the mitochondrial Ca2+ uniporter (MCU) primes mitochondria for mitophagy. Importantly, recruitment of Parkin to damaged mitochondria did not require IP3R-mediated ER-to-mitochondrial Ca2+ transfer, but mitochondrial clustering downstream of Parkin recruitment was impaired, suggesting involvement of regulators of mitochondrial dynamics and/or transport. Our data suggest that Ca2+ flux between ER and mitochondria at presumed ER/mitochondrial contact sites is needed both for starvation-induced autophagy and for Parkin-mediated mitophagy, further highlighting the importance of inter-organellar communication for effective cellular homeostasis.
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影响因子：
21.3
作者：
通讯作者：
--
影响因子：
64.5
作者：
Cárdenas C;Miller RA;Smith I;Bui T;Molgó J;Müller M;Vais H;Cheung KH;Yang J;Parker I;Thompson CB;Birnbaum MJ;Hallows KR;Foskett JK
通讯作者：
Foskett JK
影响因子：
12.4
作者：
Criollo, A.;Maiuri, M. C.;Kroemer, G.
通讯作者：
Kroemer, G.
DOI：
10.1073/pnas.1106862108
发表时间：
2011-09-13
影响因子：
11.1
作者：
Chang, Karen T.;Niescier, Robert F.;Min, Kyung-Tai
通讯作者：
Min, Kyung-Tai
DOI：
10.1016/j.bbadis.2013.01.004
发表时间：
2013-04-01
影响因子：
6.2
作者：
Cali, Tito;Ottolini, Denis;Brini, Marisa
通讯作者：
Brini, Marisa