Fung Tak Shun, Ghosh Amrapali, Zavala Maite R, Nichtova Zuzana, Shukal Dhavalkumar, Tigano Marco, Csordas Gyorgy, Higgs Henry N, Chakrabarti Rajarshi
Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
EMBO Rep. 2025 Aug 29. doi: 10.1038/s44319-025-00561-y.
Mitochondrial damage represents a dramatic change in cellular homeostasis, necessitating metabolic adaptation and clearance of the damaged organelle. One rapid response to mitochondrial damage is peri-mitochondrial actin polymerization within 2 min, which we term ADA (Acute Damage-induced Actin). ADA is vital for a metabolic shift from oxidative phosphorylation to glycolysis upon mitochondrial dysfunction. In the current study, we investigated the effect of ADA on Pink1/Parkin mediated mitochondrial quality control. We show that inhibition of proteins involved in the ADA pathway significantly accelerates Parkin recruitment onto depolarized mitochondria. Addressing the mechanism by which ADA resists Parkin recruitment onto depolarized mitochondria, we found that ADA disrupts ER-mitochondria contacts in an Arp2/3 complex-dependent manner. Interestingly, overexpression of ER-mitochondria tethers overrides the effect of ADA, allowing rapid recruitment of not only Parkin but also LC3 after mitochondrial depolarization. During chronic mitochondrial dysfunction, Parkin and LC3 recruitment are completely blocked, which is reversed rapidly by inhibiting ADA. Taken together we show that ADA acts as a protective mechanism, delaying mitophagy following acute damage, and blocking mitophagy during chronic mitochondrial damage.
线粒体损伤代表细胞内稳态的剧烈变化,需要进行代谢适应并清除受损的细胞器。对线粒体损伤的一种快速反应是在2分钟内线粒体外周肌动蛋白聚合,我们将其称为ADA(急性损伤诱导的肌动蛋白)。ADA对于线粒体功能障碍时从氧化磷酸化到糖酵解的代谢转变至关重要。在本研究中,我们研究了ADA对Pink1/Parkin介导的线粒体质量控制的影响。我们发现,抑制ADA途径中涉及的蛋白质会显著加速Parkin募集到去极化的线粒体上。在探讨ADA阻止Parkin募集到去极化线粒体上的机制时,我们发现ADA以Arp2/3复合物依赖的方式破坏内质网-线粒体接触。有趣的是,内质网-线粒体连接蛋白的过表达克服了ADA的作用,使得线粒体去极化后不仅Parkin而且LC3都能快速募集。在慢性线粒体功能障碍期间,Parkin和LC3的募集被完全阻断,而通过抑制ADA可迅速逆转这种情况。综上所述,我们表明ADA作为一种保护机制,在急性损伤后延迟线粒体自噬,并在慢性线粒体损伤期间阻断线粒体自噬。