Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
Zoological Institute, KU Leuven, 3000 Leuven, Belgium.
Biomolecules. 2022 Jul 16;12(7):991. doi: 10.3390/biom12070991.
Juvenile hormone epoxide hydrolase (JHEH) plays an important role in the metabolism of JH III in insects. To study the control of JHEH in female , JHEH 1, 2 and 3 cDNAs were cloned and sequenced. Northern blot analyses showed that the three transcripts are expressed in the head thorax, the gut, the ovaries and the fat body of females. Molecular modeling shows that the enzyme is a homodimer that binds juvenile hormone III acid (JH IIIA) at the catalytic groove better than JH III. Analyses of the three JHEH promoters and expressing short promoter sequences behind a reporter gene (Z) in cell culture identified a JHEH 3 promoter sequence (626 bp) that is 10- and 25-fold more active than the most active promoter sequences of JHEH 2 and JHEH 1, respectively. A transcription factor (TF) Sp1 that is involved in the activation of JHEH 3 promoter sequence was identified. Knocking down Sp1 using dsRNA inhibited the transcriptional activity of this promoter in transfected cells and JH III and 20HE downregulated the JHEH 3 promoter. On the other hand, JH IIIA and farnesoic acid did not affect the promoter, indicating that JH IIIA is JHEH's preferred substrate. A transgenic expressing a highly activated JHEH 3 promoter behind a Z reporter gene showed promoter transcriptional activity in many tissues.
保幼激素环氧化物水解酶（JHEH）在昆虫中 JH III 的代谢中起着重要作用。为了研究雌性保幼激素水解酶的调控，克隆并测序了 JHEH1、2 和 3 的 cDNA。Northern blot 分析表明，这三个转录本在头部胸部、肠道、卵巢和脂肪体中表达。分子建模表明，该酶是一种同二聚体，与 JH IIIA 在催化槽中的结合优于 JH III。对三个 JHEH 启动子和在细胞培养中报告基因（Z）后面表达的短启动子序列进行分析，确定了 JHEH3 启动子序列（626bp），其活性分别比 JHEH2 和 JHEH1 的最活跃启动子序列高 10 倍和 25 倍。鉴定出一个参与 JHEH3 启动子序列激活的转录因子（TF）Sp1。使用 dsRNA 敲低 Sp1 抑制了转染细胞中该启动子的转录活性，并且 JH III 和 20HE 下调了 JHEH3 启动子。另一方面，JH IIIA 和法呢酸并没有影响启动子，表明 JH IIIA 是 JHEH 的首选底物。在 Z 报告基因后面表达高度激活的 JHEH3 启动子的转基因 中，在许多 组织中显示出启动子转录活性。
