1. Activation of NIX-mediated mitophagy by an interferon regulatory factor homologue of human herpesvirus.
- Author
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Vo MT, Smith BJ, Nicholas J, and Choi YB
- Subjects
- Antiviral Agents pharmacology, Apoptosis, Cell Line, Tumor, Herpesvirus 8, Human drug effects, Herpesvirus 8, Human pathogenicity, Homeostasis, Humans, Mitochondria metabolism, Mitochondria pathology, Mitochondria virology, Protein Binding, Protein Interaction Domains and Motifs, Virus Replication drug effects, Virus Replication genetics, Herpesviridae Infections metabolism, Herpesvirus 8, Human genetics, Interferon Regulatory Factors metabolism, Membrane Proteins metabolism, Mitophagy physiology, Proto-Oncogene Proteins metabolism, Tumor Suppressor Proteins metabolism, Viral Proteins metabolism
- Abstract
Viral control of mitochondrial quality and content has emerged as an important mechanism for counteracting the host response to virus infection. Despite the knowledge of this crucial function of some viruses, little is known about how herpesviruses regulate mitochondrial homeostasis during infection. Human herpesvirus 8 (HHV-8) is an oncogenic virus causally related to AIDS-associated malignancies. Here, we show that HHV-8-encoded viral interferon regulatory factor 1 (vIRF-1) promotes mitochondrial clearance by activating mitophagy to support virus replication. Genetic interference with vIRF-1 expression or targeting to the mitochondria inhibits HHV-8 replication-induced mitophagy and leads to an accumulation of mitochondria. Moreover, vIRF-1 binds directly to a mitophagy receptor, NIX, on the mitochondria and activates NIX-mediated mitophagy to promote mitochondrial clearance. Genetic and pharmacological interruption of vIRF-1/NIX-activated mitophagy inhibits HHV-8 productive replication. Our findings uncover an essential role of vIRF-1 in mitophagy activation and promotion of HHV-8 lytic replication via this mechanism.
- Published
- 2019
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