Structure of the VAP-peptide (BmACP-6.7) gene in the silkworm, Bombyx moriand a possible regulation of its expression by BmFTZ-F1

The VAP-peptide (BmACP-6.7) is a hydrophobic peptide localized in adult cut icle of the silkworm, Bombyx mori. We isolated and characterized the VAP-pe ptide gene as a useful marker gene to analyze molecular mechanisms of termi nal differentiation processes in the adult. The gene is composed of two exo ns interrupted by one intron. The 5' upstream promoter region is shown to b ear a nucleotide sequence similar to the cia-element that is recognized and bound by the Bombyx mori FTZ-F1 protein (BmFTZ-F1). Expression of the BmFT Z-F1 gene preceded expression of the VAP-peptide gene and injection of 20-h ydroxyecdysone suppressed the expression of both genes. An in vitro binding assay indicated direct interaction of BmFTZ-F1 with the VAP-peptide gene p romoter sequence. Therefore, BmFTZ-F1 is proposed to be a possible factor r egulating the stage- specific expression of the VAP-peptide gene towards ad ult life. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.