Published online 14 July 2004
Nucleic Acids Research, Vol. 32 No. 12 © Oxford University Press 2004; all rights reserved
Transcriptional regulation of the Drosophila caudal homeobox gene by DRE/DREF
Department of Molecular Biology, College of Natural Science and 1 Research Institute of Genetic Engineering, Pusan National University, Busan 609-735, Korea, 2 Division of Biotechnology, Faculty of Textile Sciences, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan and 3 Faculty of Science, Japan Women's University, 2-8-1 Mejirodai, Bunkyouku, Tokyo 112-8679, Japan
* To whom correspondence should be addressed. Tel: +82 51 510 2278; Fax: +82 51 513 9258; Email: mayoo{at}pusan.ac.kr
The authors wish it to be known that, in their opinion, the first two authors should be regarded as joint First Authors
Received May 12, 2004; Revised and Accepted June 17, 2004
The caudal-related homeobox transcription factors are required for the normal development and differentiation of intestinal cells. Recent reports indicate that misregulation of homeotic gene expression is associated with gastrointestinal cancer in mammals. However, the molecular mechanisms that regulate expression of the caudal-related homeobox genes are poorly understood. In this study, we have identified a DNA replication-related element (DRE) in the 5' flanking region of the Drosophila caudal gene. Gel-mobility shift analysis reveals that three of the four DRE-related sequences in the caudal 5'-flanking region are recognized by the DRE-binding factor (DREF). Deletion and site-directed mutagenesis of these DRE sites results in a considerable reduction in caudal gene promoter activity. Analyses with transgenic flies carrying a caudal–lacZ fusion gene bearing wild-type or mutant DRE sites indicate that the DRE sites are required for caudal expression in vivo. These findings indicate that DRE/DREF is a key regulator of Drosophila caudal homeobox gene expression and suggest that DREs and DREF contribute to intestinal development by regulating caudal gene expression.