Sehrawat, Sapna and Khasa, Renu and Deb, Arundhati and Prajapat, Surendra Kumar and Mallick, Suvadip and Basu, Anirban and Surjit, Milan and Kalia, Manjula and Vrati, Sudhanshu (2021) Valosin-Containing Protein/p97 Plays Critical Roles in the Japanese Encephalitis Virus Life Cycle. J Virol.

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Abstract

ABSTRACTHost factors provide critical support for every aspect of the virus life cycle. We recently identified the valosin-containing protein (VCP)/p97, an abundant cellular ATPase with diverse cellular functions, as a host factor important for Japanese encephalitis virus (JEV) replication. In cultured cells, using small interfering RNA (siRNA)-mediated protein depletion and pharmacological inhibitors, we show that VCP is crucial for replication of three flaviviruses, JEV, dengue, and West Nile viruses. An FDA-approved VCP inhibitor, CB-5083, extended survival of mice in the animal model of JEV infection. While VCP depletion did not inhibit JEV attachment on cells, it delayed capsid degradation, potentially through the entrapment of the endocytosed virus in clathrin-coated vesicles (CCVs). Early during infection, VCP-depleted cells showed an increased colocalization of JEV capsid with clathrin and also higher viral RNA levels in purified CCVs. We show that VCP interacts with the JEV nonstructural protein NS5 and is an essential component of the virus replication complex. The depletion of the major VCP cofactor UFD-1 also significantly inhibited JEV replication. Thus, mechanistically, VCP affected two crucial steps of the JEV life cycle—nucleocapsid release and RNA replication. Our study establishes VCP as a common host factor with a broad antiviral potential against flaviviruses. IMPORTANCE Japanese encephalitis virus (JEV) is the leading cause of viral encephalitis epidemics in Southeast Asia, affecting mostly children, with high morbidity and mortality. Identification of host factors is thus essential for the rational design of antivirals that are urgently need as therapeutics. Here, we have identified the valosin-containing protein (VCP) as one such host-factor. This protein is highly abundant in cells and engages in diverse functions and cellular pathways by its ability to interact with different cofactors. Using small interfering RNA (siRNA)-mediated protein knockdown, we show that this protein is essential for release of the viral RNA into the cell so that it can initiate replication. The protein plays a second crucial role for the formation of the JEV replication complex. FDA-approved drugs targeting VCP show enhanced mouse survival in JE model of disease, suggesting that this could be a druggable target for flavivirus infections.

Item Type:	Article
Subjects:	Neurodegenerative Disorders Neuro-Oncological Disorders Neurocognitive Processes Neuronal Development and Regeneration Informatics and Imaging Genetics and Molecular Biology
Depositing User:	Dr. D.D. Lal
Date Deposited:	03 Aug 2021 10:05
Last Modified:	14 Dec 2021 07:39
URI:	http://nbrc.sciencecentral.in/id/eprint/738

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