Bombyx mori E26 transformation‐specific 2 (BmEts2), an Ets family protein, represses Bombyx mori Rels (BmRels)‐mediated promoter activation of antimicrobial peptide genes in the silkworm Bombyx mori

Abstract

E26 transformation-specific (Ets) family transcription factors are known to play roles in various biological phenomena, including immunity, in vertebrates. However, the mechanisms by which Ets proteins contribute to immunity in invertebrates remain poorly understood. In this study, we identified a cDNA encoding BmEts2, which is a putative orthologue of Drosophila Yan and human translocation-ets-leukemia/Ets-variant gene 6, from the silkworm Bombyx mori. Expression of the BmEts2 gene was significantly increased in the fat bodies of silkworm larvae in response to injection with Escherichia coli and Staphylococcus aureus. BmEts2 overexpression dramatically repressed B. mori Rels (BmRels)-mediated promoter activation of antimicrobial peptide genes in silkworm cells. Conversely, gene knockdown of BmEts2 significantly enhanced BmRels activity. In addition, two κB sites located on the 5' upstream region of cecropin B1 were found to be involved in the repression of BmRels-mediated promoter activation. Protein-competition analysis further demonstrated that BmEts2 competitively inhibited binding of BmRels to κB sites. Overall, BmEts2 acts as a repressor of BmRels-mediated transactivation of antimicrobial protein genes by inhibiting the binding of BmRels to κB sites.

Analyses of microRNAs and transcriptomes in the midgut of Spodoptera litura feeding on Brassica juncea

“…We found some differentially expressed transcription factors during larvae feeding on B. juncea . Ets plays a role in antioxidative stress, regulates intracellular glutathione levels and immune‐related genes (Tanaka et al ., 2012; Verschoor & Singh, 2013; Wu et al ., 2013; Tanaka et al ., 2016; Mai et al ., 2017). In this study, ets was down‐regulated after feeding on B. juncea , while most immune genes are also down‐regulated, suggesting that it might be related to regulating immune‐related genes (Table S6).…”

Spironolactone alleviates myocardial fibrosis via inhibition of Ets‑1 in mice with experimental autoimmune myocarditis

“…E26 transformation-specific (Ets) transcription factor family members share a highly conserved DNA-binding domain and are involved in cell differentiation, proliferation, metastasis, apoptosis and tissue remodeling ( 9 ). Ets sequence-1 (Ets-1), has been demonstrated to enhance fibrotic processes in the heart and in other organs.…”