A midgut-specific serine protease, BmSP36, is involved in dietary protein digestion in the silkworm, Bombyx mori

• 来源期刊: 中国昆虫科学（英文版）
• 关键词: Bombyx mori dietary digestion expression profile juvenile hormone midgut serine protease
• 年，卷（期）: 2017,（5）
• 页码范围: 753-767
• 页数: 15页
• 语种: 英文
• DOI: 10.1111/1744-7917.12369

摘要

Serine proteases play important roles in digestion and immune responses during insect development.In the present study,the serine protease gene BmSP36,which encodes a 292-residue protein,was cloned from the midgut cells ofBombyx mori.BmSP36 contains an intact catalytic triad (H57,D 102 and S 195) and a conserved substrate-binding site (G189,H216 and G226),suggesting that it is a serine protease with chymotrypsinlike specificity.The temporal and spatial expression patterns of BmSP36 indicated that its messenger RNA and protein expression mainly occurred in the midgut at the feeding stages.Westem blotting,immunofluorescence and liquid chromatography-tandem mass spectrometry analyses revealed secretion of BmSP36 protein from epithelial cells into the midgut lumen.The transcriptional and translational expression of BmSP36 was downregulated after starvation but up-regulated after refeeding.Moreover,expression of the BmSP36 gene could be up-regulated by a juvenile hormone analogue.These results enable us to better define the potential role of BmSP36 in dietary protein digestion at the feeding stages during larval development.