Biochemical characterization and functional analysis of the POU transcription factor POU-M2 of Bombyx mori

详细信息    查看全文

• 作者：Lina Liu^a ; Yu Li^a ; Yejing Wang^a ; ^b ; Peng Zhao^a ; Shuguang Wei^a ; Zhenzhen Li^a ; Huaipu Chang^a ; ^b ; Huawei He^a ; ^b ; ^{hehuawei@swu.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：POU-M2 ; Biochemical characterization ; Fibroin heavy chain ; Transcriptional regulation
• 刊名：International Journal of Biological Macromolecules
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：86
• 期：Complete
• 页码：701-708
• 全文大小：2969 K

文摘

POU-M2 is a homeodomain transcription factor which plays important roles in the development and silk synthesis of Bombyx mori. In this study, we expressed, purified and characterized POU-M2 and studied its transcription regulation on fibroin heavy chain gene of Bombyx mori. Gel filtration showed POU-M2 existed as a dimer in solution. Far-UV circular dichroism spectra indicated POU-M2 had a well-defined α-helix structure and the α-helix content was about 26.4%. The thermal unfolding transition of POU-M2 was a cooperative process. T_m, ΔH and ΔS were 45.15 ± 0.2 °C, 138.4 ± 0.5 KJ/mol and 0.4349 ± 0.04 KJ/(mol·K), respectively. Western blotting analysis indicated the expression level of POU-M2 increased slightly from day 3 to day 7 of the fifth instar larvae in the posterior silk gland. POU-M2 was positioned in the nucleus of cells. The luciferase reporter assay demonstrated POU-M2 could stimulate the promoter activity of fibroin heavy chain gene, and the activation effect was dependent on the amount of POU-M2. Our study suggested POU-M2 may be involved in the transcriptional regulation of fibroin heavy chain gene. These findings expand toward a better understanding of the structure of POU-M2 and its function in silk synthesis of Bombyx mori.