E3 ubiquitin ligase UBR5 modulates circadian rhythm by facilitating the ubiquitination and degradation of the key clock transcription factor BMAL1  

作　　者：Chun-yan Duan Yue Li Hao-yu Zhi Yao Tian Zheng-yun Huang Su-ping Chen Yang Zhang Qing Liu Liang Zhou Xiao-gang Jiang Kifayat Ullah Qing Guo Zhao-hui Liu Ying Xu Jun-hai Han Jiajie Hou Darran P O’Connor Guoqiang Xu 

机构地区：[1]Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences,Jiangsu Province Engineering Research Center of Precision Diagnostics and Therapeutics Development,Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases,Suzhou Key Laboratory of Drug Research for Prevention and Treatment of Hyperlipidemic Diseases,Soochow University,Suzhou,215123,China [2]School of Pharmacy and Biomolecular Sciences,RCSI University of Medicine and Health Sciences,123 St Stephen’s Green,Dublin 2,D02 YN77,Dublin,Ireland [3]School of Life Science and Technology,The Key Laboratory of Developmental Genes and Human Disease,Southeast University,2 Sipailou Road,Nanjing,210096,China [4]Jiangsu Key Laboratory of Neuropsychiatric Diseases and Cambridge-Suda Genomic Resource Center,Soochow University,Suzhou,215123,China [5]Department of Human Anatomy and Cytoneurobiology,Medical School of Soochow University,Suzhou,215123,China [6]Cancer Centre,Faculty of Health Sciences,University of Macao,Macao SAR,China [7]Suzhou International Joint Laboratory for Diagnosis and Treatment of Brain Diseases,College of Pharmaceutical Sciences,Soochow University,Suzhou,215123,China [8]MOE Key Laboratory of Geriatric Diseases and Immunology,Suzhou Medical College of Soochow University,Suzhou,215123,China

出　　处：《Acta Pharmacologica Sinica》2024年第9期1793-1808,共16页中国药理学报（英文版）

基　　金：National Key R&D Program of China(2019YFA0802401);National Natural Science Foundation of China(31971353);National Center for International Research(2017B01012);Jiangsu Key Laboratory of Neuropsychiatric Diseases(BM2013003);project funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.

摘　　要：The circadian clock is the inner rhythm of life activities and is controlled by a self-sustained and endogenous molecular clock,which maintains a~24 h internal oscillation.As the core element of the circadian clock,BMAL1 is susceptible to degradation through the ubiquitin-proteasome system(UPS).Nevertheless,scant information is available regarding the UPS enzymes that intricately modulate both the stability and transcriptional activity of BMAL1,affecting the cellular circadian rhythm.In this work,we identify and validate UBR5 as a new E3 ubiquitin ligase that interacts with BMAL1 by using affinity purification,mass spectrometry,and biochemical experiments.UBR5 overexpression induced BMAL1 ubiquitination,leading to diminished stability and reduced protein level of BMAL1,thereby attenuating its transcriptional activity.Consistent with this,UBR5 knockdown increases the BMAL1 protein.Domain mapping discloses that the C-terminus of BMAL1 interacts with the N-terminal domains of UBR5.Similarly,cell-line-based experiments discover that HYD,the UBR5 homolog in Drosophila,could interact with and downregulate CYCLE,the BMAL1 homolog in Drosophila.PER2-luciferase bioluminescence real-time reporting assay in a mammalian cell line and behavioral experiments in Drosophila reveal that UBR5 or hyd knockdown significantly reduces the period of the circadian clock.Therefore,our work discovers a new ubiquitin ligase UBR5 that regulates BMAL1 stability and circadian rhythm and elucidates the underlying molecular mechanism.This work provides an additional layer of complexity to the regulatory network of the circadian clock at the post-translational modification level,offering potential insights into the modulation of the dysregulated circadian rhythm.

关 键 词：BMAL1 circadian rhythm PROTEOMICS transcriptional activity UBIQUITINATION UBR5 

分 类 号：Q41[生物学—生理学]