Enteroviruses Antagonize the Host Restriction Factor ABL2 via Proteasomal Degradation to Facilitate Viral Replication.

Enteroviruses, including Coxsackievirus B3 (CVB3), are significant human pathogens that cause severe diseases, such as viral myocarditis, pancreatitis, and encephalitis. ABL proto-oncogene 2 (ABL2), a non-receptor tyrosine-protein kinase, regulates diverse physiological processes and participates in virus infection; however, its role in enterovirus infection remains uncharacterized. Here, we demonstrate a novel host-virus interaction: enteroviruses degrade ABL2 via the ubiquitin-proteasome system through their non-structural protein 2B. Furthermore, ABL2 functions as an antiviral restriction factor during enterovirus infection, specifically inhibiting the early stages of viral replication. Mechanistically, ABL2 directly interacts with RAC1, a Rho family GTPase, and downregulates RAC1 protein levels, thereby suppressing RAC1-dependent activation of the PI3K/AKT signaling pathway. In summary, our study reveals a post-translational mechanism by which enteroviruses evade host antiviral defenses, providing a rationale for therapeutic development against enteroviral diseases.