Drebrin Is Involved in the Life Cycle of Pseudorabies Virus by Regulating the Actin Cytoskeleton.

Pseudorabies virus (PRV), a highly pathogenic alphaherpesvirus, poses a potential threat to public health and safety due to its broad host range and risk of cross-species transmission. Viruses have evolved multiple strategies to exploit host factors for entry into and survival in host cells. Drebrin is an actin-binding protein that restricts rotavirus entry by inhibiting dynamin-mediated endocytosis. However, its role and mechanism in DNA virus infection, particularly in herpesviruses, remain unexplored. In this study, we investigated the role of Drebrin in PRV infection using pharmacological inhibition (BTP-2) and CRISPR-Cas9-mediated gene knockout. Both the Drebrin inhibitor BTP-2 and gene knockout significantly suppressed PRV replication. Intriguingly, Drebrin exhibited stage-specific effects on the viral life cycle: its inhibition enhanced viral internalization during early infection but impaired viral replication at later stages, suggesting that Drebrin plays a complex role in the regulation of PRV infection. PRV infection partially disrupted actin stress fibers and caused an increase in cell size. Drebrin knockout also altered the host-cell morphology, reduced the cell surface area, and induced actin cytoskeleton rearrangement, which was further modulated in PRV-infected cells. In summary, our data demonstrate that Drebrin functions as a critical host factor governing the entire PRV life cycle by regulating actin cytoskeleton reorganization.