正如我们所知,诱导性是P450基因的重要特征。先前的研究表明,CYP6B7可以诱导并参与氰戊菊酯的解毒作用。然而,氰戊菊酯诱导CYP6B7的调控机制尚不清楚。在这项研究中,克隆了棉铃虫CYP6B7启动子,并鉴定了氰戊菊酯的顺式作用元件位于CYP6B7启动子的-84和-55bp之间。随后,33个候选转录因子(CYP6B7-氰戊菊酯相关蛋白,筛选了可能与顺式作用元件结合的CAPs),并通过酵母单杂交进行了验证。其中,氰戊菊酯显著诱导了几种CAPs的表达水平。幼体激素结合蛋白样(JHBP)的敲低,RNA聚合酶II相关蛋白3(RPAP3),脂肪酸合成酶样(FAS)和肽聚糖识别蛋白LB样(PGRP)导致CYP6B7的表达受到显着抑制,并增加了棉铃虫对氰戊菊酯的敏感性。报告基因p(-84/-55)与pFast-CAP共转染表明,RPAP3和PGRP可以显著增长CYP6B7启动子的活性。这些结果表明,反式作用因子JHBP,RPAP3和PGRP可能与顺式作用元件结合调节氰戊菊酯诱导的CYP6B7的表达,并在棉铃虫对氰戊菊酯的解毒中发挥重要作用。
As we known, inducibility is an important feature of P450 genes. Previous studies indicated that
CYP6B7 could be induced and involved in fenvalerate detoxification in Helicoverpa armigera. However, the regulatory mechanism of
CYP6B7 induced by fenvalerate is still unclear. In this study,
CYP6B7 promoter of H. armigera was cloned and the cis-acting element of fenvalerate was identified to be located between -84 and - 55 bp of
CYP6B7 promoter. Subsequently, 33 candidate transcription factors (
CYP6B7-fenvalerate association proteins, CAPs) that may bind to the cis-acting element were screened and verified by yeast one-hybrid. Among them, the expression levels of several CAPs were significantly induced by fenvalerate. Knockdown of juvenile hormone-binding protein-like (JHBP), RNA polymerase II-associated protein 3 (RPAP3), fatty acid synthase-like (FAS) and peptidoglycan recognition protein LB-like (PGRP) resulted in significant expression inhibition of CYP6B7, and increased sensitivity of H. armigera to fenvalerate. Co-transfection of reporter gene p (-84/-55) with pFast-CAP showed that JHBP, RPAP3 and PGRP could significantly increase the activity of CYP6B7 promoter. These results suggested that trans-acting factors JHBP, RPAP3 and PGRP may bind with cis-acting elements to regulate the expression of CYP6B7 induced by fenvalerate, and play an important role in the detoxification of H. armigera to fenvalerate.