Molecular cloning and characterization of C 1 tetrahydrofolate (C 1 -THF) synthase in Bombyx mori, silkworm

• Published in: Gene Vol. 663; p. 25
• Main Authors: Chen, Meijun, Zhai, Jingjie, Liu, Yu, Xue, Bin, Hu, Jiahuan, Cheng, Xiaoyu, Li, Jinxin, Hu, Jingsheng, Li, Bing
• Format: Journal Article
• Language: English
• Published: Netherlands 15.07.2018
• Subjects: Folate metabolism; Oxidative stress; High temperature; Phoxim
• ISSN: 1879-0038
• DOI: 10.1016/j.gene.2018.04.037

Folate metabolism pathway is mainly associated with syntheses of nucleic acids and proteins as well as DNA methylation and repair. Cytoplasmic C tetrahydrofolate (C -THF) synthase is a central enzyme in folate metabolism and plays an important role in C -THF conversion. The full-length sequence of silkworm (Bombyx mori) cytoplasmic C -THF synthase (BmC -THF synthase) gene including an open reading frame (ORF) of 932 amino acid residues was cloned. Phylogenetic analysis indicated that BmC -THF synthase shares 84% and 81% identity with C -THF synthase of Papilio Xuthus and Danaus plexippus, respectively. Conserved sequence analysis showed that the 330 to 710 amino acid residues of BmC -THF synthase were highly conserved among various organisms. Recombinant BmC -THF synthase protein with a molecular weight of about 105.5 kDa was expressed in E. coli cells and identified using SDS-PAGE and western blot analysis. The expression of BmC -THF synthase gene in eight silkworm tissues revealed that BmC -THF synthase gene is widely expressed in various tissues of silkworm and highly expressed in the fat body. The expression characteristics of BmC -THF synthase gene in response to oxidative stress were conducted under phoxim and high temperature (30 °C) exposure. The results showed that the transcriptional level of BmC -THF synthase gene was upregulated by 3.435-fold and 6.845-fold after phoxim and high temperature (30 °C) exposure, respectively, indicating that BmC -THF synthase gene may play a significant role in response of silkworm to oxidative stresses.