Rotavirus-NSP5 Interacts with and Hijacks Host ATP Citrate Lyase to Viroplasms, Enhancing Lipid Biosynthesis for Facilitating Rotavirus Infection

Rotavirus (RV) replication occurs within viroplasms (VMs) and is initiated by two RV non-structural proteins NSP2 and NSP5. Viruses exploit host cellular components for their replication and assembly; however, information on the roles of host proteins in VM dynamics and RV replication is limited. Thus, in the current study, we used proteomics to identify host proteins that interact with NSP5 during RV infection to delineate their role in virus replication. A large number of host proteins (n = 128) were found to interact with NSP5, and Gene Ontology enrichment analysis revealed the enrichment of various metabolic processes during RV infection. One of the essential host proteins, ATP citrate lyase (ACLY), which is involved in the de novo lipid synthesis pathway, was found to interact with C-terminal region of RV-NSP5 and colocalize within VMs. Following RV infection, the serine 455 phosphorylation of ACLY was induced, suggesting increased enzymatic activation. This correlates with enhanced lipid droplet production via increased acetyl-coenzyme A expression levels, which in turn supports VM formation. The ACLY inhibitors SB204990 or hydroxycitric acid tripotassium hydrate significantly reduced RV-infection in vitro. This anti-rotaviral effect of drug was further validated in BALB/c suckling mice by measuring viral protein expression and viral titers. In the presence of ACLY inhibitor, reduced viral titers, reduced viral protein expression, and improved small intestinal histopathology were observed. These findings suggest a protective effect of drugs against RV infection in vivo and highlight ACLY as a potential anti-rotaviral target for the development of new therapeutics.