Big brain, a Drosophila homologue of mammalian aquaporin, is regulated by the DRE/DREF system.
Drosophila big brain (bib) encodes for a protein similar to members of the major intrinsic protein family, which includes the water- and ion-conducting aquaporin (AQP) channels. In mammals, AQP dysregulation has been implicated in a variety of diseases, including colorectal cancer and colonic injury. However, the regulatory mechanisms of AQP expression remain to be clearly elucidated. In this study, as we found a DREF binding site (DRE) in the 5'-flanking regions of both the Drosophila bib gene and the human AQP1 gene, we assessed the role of DREF in bib gene expression. DREF in Drosophila and humans has been demonstrated to function as a key transcriptional activator for cell proliferation-related genes. Herein, we demonstrate that the DRE is required for optimal promoter activity of Drosophila bib gene, particularly in the larval imaginal discs, which are actively proliferating tissues, as well as the adult hindgut. Our results may provide insight into the mechanisms inherent to the regulation of mammalian AQP genes.
Park
Joung-Sun
JS
Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 609-735, Republic of Korea.
Kim
Su-Ryun
SR
Park
So-Young
SY
Yang
Dong-Jin
DJ
Lee
Shin-Hae
SH
Choi
Yoon-Jeong
YJ
Bae
Moon-Kyoung
MK
Yamaguchi
Masamitsu
M
Kim
Young-Shin
YS
Yoo
Mi-Ae
MA