title: Cell Entry of Porcine Epidemic Diarrhea Coronavirus Is Activated by Lysosomal Proteases.
abstract: Porcine epidemic diarrhea coronavirus (PEDV) is currently devastating the United States pork industry by causing an 80-100% fatality rate in infected piglets. Coronavirus spike proteins mediate virus entry into cells, a process that requires the spike proteins to be proteolytically activated. It has been a conundrum which proteases activate PEDV entry. Here we systematically investigated the roles of different proteases in PEDV entry using pseudovirus entry, biochemical, and live virus infection assays. We found that the PEDV spike is activated by lysosomal cysteine proteases but not proprotein convertases or cell surface serine proteases. Extracellular trypsin activates PEDV entry when lysosomal cysteine proteases are inhibited. We further pinpointed cathepsin L and cathepsin B as the lysosomal cysteine proteases that activate the PEDV spike. These results advance our understanding of the molecular mechanism for PEDV entry and identify potential antiviral targets for curbing the spread of PEDV.
authors.affiliation: From the Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: the Department of Veterinary Biosciences, College of Veterinary Medicine, Ohio State University, Columbus, Ohio 43210.
authors.forename: Yuanmei
authors.initials: Y
authors.lastname: Ma
authors.affiliation: From the Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: From the Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: From the Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455.
authors.forename: Jian
authors.initials: J
authors.lastname: Shang
authors.affiliation: the State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.
authors.forename: Yusen
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: the Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10065, and; the Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medicine, Fudan University, Shanghai 200032, China.
authors.forename: Shibo
authors.initials: S
authors.lastname: Jiang
authors.affiliation: the Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10065, and.
authors.forename: Lanying
authors.initials: L
authors.lastname: Du
authors.affiliation: the Department of Veterinary Biosciences, College of Veterinary Medicine, Ohio State University, Columbus, Ohio 43210,. Electronic address: li.926@osu.edu.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Li
authors.affiliation: From the Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455,. Electronic address: lifang@umn.edu.
authors.forename: Fang
authors.initials: F
authors.lastname: Li
mesh_terms: D000818:Animals; D002401:Cathepsin B / Q000378:metabolism*; D056668:Cathepsin L / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D008247:Lysosomes / Q000201:enzymology* / Q000821:virology; D053485:Porcine epidemic diarrhea virus / Q000502:physiology*; D064370:Spike Glycoprotein, Coronavirus / Q000378:metabolism*; D013552:Swine; D053586:Virus Internalization
chemical_list: D064370:Spike Glycoprotein, Coronavirus; C533912:CTSB protein, human; D002401:Cathepsin B; C534281:CTSL protein, human; D056668:Cathepsin L
keywords: cysteine protease; membrane fusion; protease inhibitor; proteolysis; virus entry