Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Republic of Singapore.
Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA.
Cell Death Differ. 2021 Mar;28(3):827-842. doi: 10.1038/s41418-020-00657-z. Epub 2020 Nov 18.
Most cellular stress responses converge on the mitochondria. Consequently, the mitochondria must rapidly respond to maintain cellular homeostasis and physiological demands by fine-tuning a plethora of mitochondria-associated processes. The outer mitochondrial membrane (OMM) proteins are central to mediating mitochondrial dynamics, coupled with continuous fission and fusion. These OMM proteins also have vital roles in controlling mitochondrial quality and serving as mitophagic receptors for autophagosome enclosure during mitophagy. Mitochondrial fission segregates impaired mitochondria in smaller sizes from the mother mitochondria and may favor mitophagy for eliminating damaged mitochondria. Conversely, mitochondrial fusion mixes dysfunctional mitochondria with healthy ones to repair the damage by diluting the impaired components and consequently prevents mitochondrial clearance via mitophagy. Despite extensive research efforts into deciphering the interplay between fission-fusion and mitophagy, it is still not clear whether mitochondrial fission essentially precedes mitophagy. In this review, we summarize recent breakthroughs concerning OMM research, and dissect the functions of these proteins in mitophagy from their traditional roles in fission-fusion dynamics, in response to distinct context, at the intersection of the OMM platform. These insights into the OMM proteins in mechanistic researches would lead to new aspects of mitochondrial quality control and better understanding of mitochondrial homeostasis intimately tied to pathological impacts.
大多数细胞应激反应都集中在线粒体。因此,线粒体必须迅速做出反应,通过微调大量与线粒体相关的过程来维持细胞内稳态和生理需求。外膜蛋白(OMM)是介导线粒体动力学的核心,与不断的分裂和融合相耦合。这些 OMM 蛋白在控制线粒体质量和作为自噬体在自噬期间包裹的噬线粒体受体方面也起着至关重要的作用。线粒体分裂将受损的线粒体从母线粒体中分离成较小的尺寸,可能有利于通过自噬来消除受损的线粒体。相反,线粒体融合将功能失调的线粒体与健康的线粒体混合在一起,通过稀释受损的成分来修复损伤,从而防止通过自噬进行线粒体清除。尽管人们在破译分裂-融合和自噬之间的相互作用方面进行了广泛的研究,但线粒体分裂是否先于自噬仍然不清楚。在这篇综述中,我们总结了最近关于 OMM 研究的突破,并从传统的分裂-融合动力学角色出发,剖析了这些蛋白质在自噬中的功能,以应对不同的背景,在 OMM 平台的交汇处。这些关于 OMM 蛋白在机制研究中的见解将为线粒体质量控制带来新的方面,并更好地理解与病理影响密切相关的线粒体动态平衡。