Ribosomal Protein L11 Mediates Antiviral Defense via Activation of Apoptosis in Bombyx mori.

Ribosomal protein L11 (RPL11) plays important roles in ribosome biogenesis and stress responses, yet its antiviral function remains poorly understood. This study characterized BmRPL11 and its role in Bombyx mori nucleopolyhedrovirus (BmNPV) infection. BmRPL11 is evolutionarily conserved and shares high sequence homology and protein structure with RPL11 from other species. Tissue expression profiling showed predominant BmRPL11 expression in silk glands and the fat body, with upregulation after BmNPV infection. Functional assays demonstrated that BmRPL11 knockdown enhanced, whereas overexpression suppressed, BmNPV proliferation in BmN cells and silkworm larvae. Mechanistically, BmNPV infection induced nuclear export of BmRPL11 and was associated with enhanced apoptosis, while autophagy-related genes were not markedly affected by BmRPL11 knockdown. IP-MS identified candidate BmRPL11-interacting proteins during infection, including RPL5, whereas a canonical murine double minute 2 (MDM2) homologue was not detected. These findings identify BmRPL11 as an antiviral factor in silkworms, potentially acting through an apoptotic rather than an autophagic pathway.