Rotaviral non ‐structural protein 4 triggers Dynamin related protein 1‐dependent mitochondrial fragmentation during infection

Abstract Dynamic equilibrium between mitochondrial fission and mitochondrial fusion serves as an important quality control system within cells ensuring cellular vitality and homeostasis. Viruses often target mitochondrial dynamics as a part of their obligatory cellular reprogramming. The present study was undertaken to assess the status and regulation of mitochondrial dynamics during rotavirus (RV) infection. Distinct fragmentation of mitochondrial syncytia was observed during late hours of RV (SA11, Wa, A5‐13) infection. RV non‐structural protein 4 (NSP4) was identified as the viral trigger for disrupted mitochondrial morphology. Severance of mitochondrial interconnections was found to be a Dynamin related protein 1 (Drp1)‐dependent process resulting synergistically from augmented mitochondrial fission and attenuated mitochondrial fusion. Cyclin dependent kinase 1 (Cdk1) was subsequently identified as the cellular kinase responsible for fission‐active Ser616 phosphorylation of Drp1. In addition to its positive role in mitochondrial fission, Drp1 also resulted in mitochondrial translocation of E3‐ubiquitin ligase Parkin leading to degradation of mitochondrial fusion protein Mitofusin 1 (Mfn1). Interestingly, RV‐NSP4 was found to interact with and be involved in recruiting fission‐active pool of Serine 616 phosphoDrp1 (Ser616 pDrp1) to mitochondria independent of accessory adaptors Mitochondrial fission factor (Mff) and Fission protein 1 (Fis1). Inhibition of eit...
Source: Cellular Microbiology - Category: Microbiology Authors: Tags: RESEARCH ARTICLE Source Type: research