Abstract：
Juvenile hormone epoxide hydrolase (JHEH) plays an important role in the metabolism of juvenile hormone III (JH III) in insects. To study the role that JHEH plays in female Aedes aegypti JHEH 1, 2, and 3 complementary DNA (cDNAs) were cloned and sequenced. Northern blot analyses show 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 JH III acid (JH IIIA) at the catalytic groove better than JH III. The cDNA of JHEH 1 and 2 are very similar indicating close relationship. Knocking down of jheh 1, 2, and 3 in adult female and larval Ae. aegypti using double-stranded RNA (dsRNA) did not affect egg development or caused adult mortality. Larvae that were fed bacterial cells expressing dsRNA against jheh 1, 2, and 3 grew normally. Treating blood-fed female Ae. aegypti with [12-3 H](10R) JH III and analyzing the metabolites by C18 reversed phase chromatography showed that JHEH preferred substrate is not JH III but JH IIIA. Genomic analysis of jheh 1, 2, and 3 indicate that jheh 1 and 2 are transcribed from a 1.53 kb DNA whereas jheh 3 is transcribed from a 10.9 kb DNA. All three genes are found on chromosome two at distinct locations. JHEH 2 was expressed in bacterial cells and purified by Ni affinity chromatography. Sequencing of the recombinant protein by MS/MS identified JHEH 2 as the expressed recombinant protein.
摘要：
幼体激素环氧化物水解酶(JHEH)在昆虫幼体激素Ⅲ(JHⅢ)的代谢中起重要作用。为了研究JHEH在雌性埃及伊蚊中的作用，克隆并测序了JHEH1、2和3互补DNA（cDNA）。Northern印迹分析显示三个转录本在头部胸部表达,肠道，卵巢,和女性肥胖的身体。分子建模表明，该酶是一种同型二聚体，在催化凹槽处比JHIII更好地结合JHIII酸（JHIIIA）。JHEH1和2的cDNA非常相似，表明关系密切。在成年雌性和幼虫Ae中击倒jheh1、2和3。使用双链RNA（dsRNA）的埃及伊蚊不会影响卵发育或导致成人死亡。饲喂表达针对jheh1、2和3的dsRNA的细菌细胞的幼虫正常生长。治疗以血液喂养的女性Ae。用[12-3H]（10R）JHIII和C18反相色谱法分析代谢物表明，JHEH首选底物不是JHIII，而是JHIIIA。对jheh1、2和3的基因组分析表明，jheh1和2是从1.53kbDNA转录的，而jheh3是从10.9kbDNA转录的。所有三个基因都在染色体2的不同位置发现。JHEH2在细菌细胞中表达，并用Ni亲和层析纯化。通过MS/MS对重组蛋白的测序鉴定JHEH2为表达的重组蛋白。
