Luhao Zhang ^1,2 Xuechun Liu ¹ Min Zhu ¹ Yuanfa Yao ¹ Zhichao Liu ¹ Xianming Zhang ¹ Xin Deng ³ Yi Wang ⁴ Liting Duan ⁵ Xiaogang Guo ⁶ Junfen Fu ³ Yingke Xu ^1,2,3*

• ¹ Zhejiang University, Hangzhou, China
• ² Binjiang Institute of Zhejiang University, Hangzhou, Jiangsu Province, China
• ³ Department of Endocrinology, Children's Hospital, School of Medicine, ZheJiang University, Hangzhou, Jiangsu Province, China
• ⁴ Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Jiangsu Province, China
• ⁵ Department of Biomedical Engineering, Faculty of Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong Region, China
• ⁶ Department of Cardiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Jiangsu Province, China

The balance of mitochondrial fission and fusion plays an important role in maintaining the stability of cellular homeostasis. Abnormal mitochondrial fission and fragmentation have shown to be associated with oxidative stress, which causes diverse human diseases from neurodegeneration disease to cancer. Therefore, induction of mitochondrial aggregation and fusion may provide an alternative approach to alleviate these conditions. Here, the optogenetic based mitochondrial aggregation system (Opto-MitoA) is developed, which is based on the CRY2clust/CIBN light-sensitive module.Upon blue light illumination, CRY2clust relocates from the cytosol to mitochondria, where it induced mitochondrial aggregation by CRY2clust homo-oligomerization and CRY2clust-CIBN hetero-dimerization. Our functional experiments demonstrated that Opto-MitoA induced mitochondrial aggregation potently alleviates niclosamide caused cell dysfunction in ATP production. This study established a novel optogenetic based strategy to regulate mitochondrial dynamics in cell, which may provide a potential therapy for the treatment of mitochondrial related diseases.