Bombyx mori transcription factor, E74A, beneficially affects BmNPV infection through direct interaction

Abstract

BACKGROUND: Nucleopolyhedrovirus (NPV), one of the baculoviruses, is a promising biopesticide for pest control. Lepidopteran account for 70% of pests, therefore investigation on highly conserved genes associated with viral infections in the lepidopteran model, the silkworm, will serve as a valuable reference for improving the effectiveness of pest management. BmE74A is a member of the erythroblast transformation-specific (ETS) family of transcription factors in Bombyx mori, which we previously found to be highly conserved and closely associated with BmNPV. This study aimed to elucidate the role of BmE74A in viral infection.RESULTS: A significantly high expression of BmE74A in eggs indicated its important role in embryonic development, as did relatively high expressions in the hemolymph and midgut. Significant differences in BmE74A expression in different resistant strains after BmNPV infection suggested its involvement as a response to viral infection. Moreover, RNA interference (RNAi) and overexpression experiments confirmed the important role of BmE74A in promoting viral infection. BmNPV infection was significantly suppressed and enhanced by BmE74A knockdown and overexpression, respectively. Besides, BmE74A was found to regulate the expression of BmMdm2 and Bmp53. Furthermore, the binding of ETS, the functional domain of BmE74A, to occlusion-derived virus proteins was confirmed by far-western blotting, and four viral proteins that may interact with ETS proteins were identified by mass spectrometry. Similarly, a homolog of BmE74A in Spodoptera litura was also found to be involved in larval susceptibility to BmNPV. CONCLUSION: BmE74A promotes BmNPV proliferation by directly interacting with the virus, which may be related to the suppression of the p53 pathway.

MicroRNA-Mediated Host Immune Genes Manipulation Benefits AcMNPV Proliferation in Spodoptera frugiperda

“…Intriguingly, p53 , the target gene of mse-miR-317, is known to play a key role during viral infection in several insect species by rapidly inducing apoptosis. − Eip74EF , a gene essential for development, was significantly suppressed by sfr-miR-10494-3p. BmE74A , reported in silkworms, promotes BmNPV proliferation by directly interacting with viruses . In S. frugiperda , AIF1 is crucial during stress-induced apoptosis .…”

“…BmE74A, reported in silkworms, promotes BmNPV proliferation by directly interacting with viruses. 59 In S. frugiperda, AIF1 is crucial during stress-induced apoptosis. 60 Similarly, Eiger-2 was significantly suppressed by novel-miR-153.…”

MicroRNA bmo‐miR‐31‐5p inhibits apoptosis and promotes BmNPV proliferation by targeting the CYP9e2 gene of Bombyx mori

“…5 During BmNPV infection, the silkworm transcription factor BmE74A may enhance virus proliferation by suppressing the p53 pathway. 6 However, more research is needed to reveal the mechanism of apoptosis in the interaction between viruses and hosts.…”

Identification of the transcription factor E74A gene from Chilo suppressalis which is essential for vitellogenesis

“…20E induced E74A was shown to regulate the expression of ecdysone oxidase gene ( BmEO ) in Bombyx mori , affecting the titer of ecdysone. Furthermore, BmE74A participates in the reaction of B. mori Nucleopolyhedrovirus ( BmNPV ) infecting B. mori (Sun et al, 2017; Wang et al, 2022). However, it is unclear if the transcription factor E74A is involved in regulating vitellogenin in Lepidoptera.…”