Molecular, Cellular and Developmental Biology Department, University of Michigan, Ann Arbor, Michigan, United States of America.
Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary.
PLoS Genet. 2021 Aug 12;17(8):e1009731. doi: 10.1371/journal.pgen.1009731. eCollection 2021 Aug.
A healthy population of mitochondria, maintained by proper fission, fusion, and degradation, is critical for the long-term survival and function of neurons. Here, our discovery of mitophagy intermediates in fission-impaired Drosophila neurons brings new perspective into the relationship between mitochondrial fission and mitophagy. Neurons lacking either the ataxia disease gene Vps13D or the dynamin related protein Drp1 contain enlarged mitochondria that are engaged with autophagy machinery and also lack matrix components. Reporter assays combined with genetic studies imply that mitophagy both initiates and is completed in Drp1 impaired neurons, but fails to complete in Vps13D impaired neurons, which accumulate compromised mitochondria within stalled mito-phagophores. Our findings imply that in fission-defective neurons, mitophagy becomes induced, and that the lipid channel containing protein Vps13D has separable functions in mitochondrial fission and phagophore elongation.
健康的线粒体群体,通过适当的分裂、融合和降解来维持,对神经元的长期存活和功能至关重要。在这里,我们在分裂受损的果蝇神经元中发现了噬线粒体中间产物,为线粒体分裂和噬线粒体之间的关系提供了新的视角。缺乏共济失调疾病基因 Vps13D 或动力相关蛋白 Drp1 的神经元含有增大的线粒体,这些线粒体与自噬机制结合,并且缺乏基质成分。报告基因分析与遗传研究表明,噬线粒体在 Drp1 受损神经元中既起始又完成,但在 Vps13D 受损神经元中不能完成,Vps13D 受损神经元中的停滞的噬线粒体中积累了受损的线粒体。我们的发现表明,在分裂缺陷的神经元中,噬线粒体被诱导,并且含有脂质通道的蛋白 Vps13D 在线粒体分裂和吞噬体延伸中具有可分离的功能。