A Kinase Chaperones Hepatitis B Virus Capsid Assembly and Captures Capsid Dynamics in vitro

摘要: The C-terminal domain (CTD) of Hepatitis B virus (HBV) core protein is involved in regulating multiple stages the HBV lifecycle. CTD phosphorylation correlates with pregenomic-RNA encapsidation during capsid assembly, reverse transcription, and viral transport, although mechanisms remain unknown. In vitro, purified (Cp183) binds any RNA assembles aggressively, independent phosphorylation, to form empty RNA-filled capsids. We hypothesize that there must be a chaperone prevent self-assembly nonspecific packaging. Here, we show assembly stalled by Serine Arginine kinase (SRPK) binding CTD, reactivated subsequent phosphorylation. Using SRPK probe capsids, solution structural studies showed bound capsid, though sequestered on interior. This result indicates transient externalization suggests dynamics could crucial for directing intracellular trafficking. Our illustrate stochastic nature capsids demonstrate appropriation host non-canonical function.