Transcriptional regulation of the gene for prothoracicotropic hormone in the silkworm, Bombyx mori.

Prothoracicotropic hormone is one of key players in regulation of insect growth, molting, metamorphosis, diapause, and is expressed specifically in the two pairs of lateral neurosecretory cells in the brain. Analysis of cis-regulatory elements of the promoter might elucidate the regulatory mechanism controlling duanyu1547H expression. In this study, the duanyu1547H gene promoter of Bombyx mori was cloned and sequenced. The cis-regulatory elements in gene promoter were predicted using Matinspector software, including myocyte-specific enhancer factor 2, pre-B-cell leukemia homeobox 1, TATA box, etc. Transient transfection assays using a series of fragments linked to the luciferase reporter gene indicated that the fragment spanning -110 to +33 bp of the Bom-duanyu1547H promoter showed high ability to support reporter gene expression, but the region of +34 to +192 bp and -512 to -111 bp repressed the promoter activity in the BmN and Bm5 cell lines. Electrophoretic mobility shift assays demonstrated that the nuclear protein could specifically bind to the region spanning -124 to -6 bp of the Bom-duanyu1547H promoter. Furthermore, we observed that the nuclear protein could specifically bind to the -59 to -30 bp region of the Bom-duanyu1547H promoter. A classical TATA box, TATATAA, localized at positions -47 to -41 bp, which is a potential site for interaction with TATA box binding protein (TBP). Mutation of this TATA box resulted in no distinct binding band. Taken together, TATA box was involved in regulation of duanyu1547H gene expression in B. mori.

KEYWORDS: {{ getKeywords(articleDetailText.words) }}