BmEts upregulates promoter activity of lebocin in Bombyx mori

► Gene expression of BmEts was upregulated in response to bacterial injection in the silkworm larvae. ► BmEts enhanced promoter activity of lebocin. ► BmEts synergistically enhanced E. coli or BmRelish1-stimulated lebocin promoter activation. ► Two κB elements and a GGAA/T motif were involved in BmEts-mediated lebocin promoter activation. ► BmEts interacted with BmRelish1 in vitro.