Liquid-liquid Phase Separation in Viral Function

• Published in: Journal of molecular biology 2023-08, Vol.435 (16), p.167955, Article 167955
• Main Authors: Zhang, Xiaoyue, Zheng, Run, Li, Zhengshuo, Ma, Jian
• Format: Article
• Language: English
• Subjects: antiviral immunity; biomolecular condensate; Liquid-liquid phase separation; viral factories
• ISSN: 0022-2836; 1089-8638
• DOI: 10.1016/j.jmb.2023.167955

During viral infection, the replication and assembly of many viruses occurs in specialized intracellular compartments. These structures are called viral factories, replication compartments (RCs), viral inclusion bodies (IBs), stress granules(SGs), Negri bodies (NBs) and cytoplasmic virion assembly compartments (cVACs). They condense viral proteins, nucleic acids and cellular factors, enabling the essential steps of viral replication while simultaneously protecting the viral genome from cellular defenses. [Display omitted] •Liquid-liquid phase separation (LLPS) is involved in the composition of various subcellular membrane-less compartments.•LLPS may play a role in the formation and maintenance of these viral factories over the life cycle of DNA or RNA viruses.•This review provides an opportunity to understand the function and mechanism of phase-separated viral factories. An emerging set of results suggests that liquid-liquid phase separation (LLPS) is the basis for the formation of membrane-less compartments in cells. Evidence is now mounting that various types of virus-induced membrane-less compartments and organelles are also assembled via LLPS. Specifically, viruses appear to use intracellular phase transitions to form subcellular microenvironments known as viral factories, inclusion bodies, or viroplasms. These compartments - collectively referred to as viral biomolecular condensates - can be used to concentrate replicase proteins, viral genomes, and host proteins that are required for virus replication. They can also be used to subvert or avoid the intracellular immune response. This review examines how certain DNA or RNA viruses drive the formation of viral condensates, the possible biological functions of those condensates, and the biophysical and biochemical basis for their assembly.