Here, we investigated the role of acyl-coenzyme A binding domain containing 3 (ACBD3) in PI4KB recruitment upon enterovirus replication using ACBD3 knockout (ACBD3<sup>KO</sup>) cells.
This work supports a two-step resistance model of enterovirus to PI4KB/OSBP inhibitors involving unique recessive epistasis of 3A and 2B and offers insights into a potential evolutionary pathway of enterovirus toward independence from the PI4KB/OSBP pathway.
These findings suggest that interaction of PI4KB with these host proteins is not essential for EV replication once PI4KB has been expressed and that PI4KB is functionally independent from these host proteins regarding EV replication.
These results reveal a mechanism of enterovirus replication that involves a selective strategy for recruitment of PI4KB to the RNA replication sites.<b>IMPORTANCE</b> Enterovirus 71, like other human enteroviruses, replicates its genome within host cells, where viral proteins efficiently utilize cellular machineries.
Although enterovirus replication depends on phosphatidylinositol 4-kinase type IIIβ (PI4KB), its role, and that of its product, phosphatidylinositol 4-phosphate (PI4P), is only partially understood.
Enterovirus mutants resistant to inhibitors of PI4KB and OSBP were previously isolated, which demonstrated a role of single substitutions in the non-structural 3A protein in conferring resistance.
To date, ARF1, ACBD3, BIG1/BIG2, GBF1, RTN3, and PI4KB have been identified as host factors of enterovirus (EV), including PV, involved in membrane traffic.
Here, we report use of a novel activity-based probe, PIKBPyne, which labels phosphatidylinositol kinases (PIKs) in an activity-based manner, to investigate HCV-dependent changes in protein-protein interactions for PI4KB.
Thus, these compounds exert selective nanomolar or even subnanomolar activity against PI4KB as well as profound antiviral effect against hepatitis C virus, human rhinovirus, and coxsackievirus B3.
The lipid kinase phosphatidylinositol 4-kinase IIIβ (PI4KB) is an essential host factor for many positive-sense single-stranded RNA (+RNA) viruses including human pathogens hepatitis C virus (HCV), Severe acute respiratory syndrome (SARS), coxsackie viruses, and rhinoviruses.
The lipid kinase phosphatidylinositol 4-kinase IIIβ (PI4KB) is an essential host factor for many positive-sense single-stranded RNA (+RNA) viruses including human pathogens hepatitis C virus (HCV), Severe acute respiratory syndrome (SARS), coxsackie viruses, and rhinoviruses.