Transcription Element Responsible for the Brain Cell-Specific Expression of the Bombyxin Gene that Encodes an Insect Insulin-related Peptide

Abstract

Abstract Invertebrate insulin-related peptides play key roles in growth and metabolism. Genes encoding these peptides are specifically expressed in neurosecretory cells. Bombyxin genes of the silkmoth Bombyx mori encode insulin-related peptides and are expressed in four pairs of the neurosecretory cells in pars intercerebralis of brain. No regulatory element has been identified to confer the neurosecretory cell-specific expression of bombyxin gene. By promoter-deletion analysis and in vitro electroporation, we identified a transcription element essential for the cell-specific expression of bombyxin F1 gene, one of the bombyxin multifamily genes. The element was localized in the region from −170 to −159 bp upstream of the translation start site of the F1 gene. We named the element as BOSE, BOmbyxin gene-Specific Element. No protein that would bind to BOSE was found by searching the transcription factors database. In addition, an activator element responsible for increasing the expression level was identifi...