Insects utilize xenobiotic compounds to up-and downregulate cytochrome P450 monooxygenases(P450s)involved in detoxification of toxic xenobiotics including phytochemicals and pesticides.G-quadruplexes(G4)-forming DNA motifs are enriched in the promoter regions of transcription factors and function as cis-acting elements to regulate these genes.Whether and how P450s gain and keep G4 DNA motifs to regulate their expression still remain unexplored.Here,we show that CYP321A1,a xenobiotic-metabolizing P450 from Helicoverpa zea,a polyphagous insect of economic importance,has acquired and preserved a G4 DNA motif by selectively retaining a transposon known as HzISl-3 that carries this G4 DNA motif in its promoter region.The HzIS1-3 G4 DNA motif acts as a silencer to suppress the constitutive and induced expression of CYP321A1 by plant allelochemicals flavone and xanthotoxin through folding into an intramolecular parallel or hybrid-1 conformation in the absence or presence of K+.The G4 ligand N-methylmesoporphyrin IX(NMM)strengthens the silencing effect of HzIS1-3 G4 DNA motif by switching its structure from hybrid-1 to hybrid-2.The enrichment of transposons in P450s and other environment-adaptation genes implies that selective retention of G4 DNA motif-carrying transposons may be the main evolutionary route for these genes to obtain G4 DNA motifs.

Zhongyuan Deng;Yuting Zhang;Chao Gao;Wei Shen;Shan Wang;Xinzhi Ni;Sisi Liu;Xianchun Li

School of Agricultural Sciences,Zhengzhou University,Zhengzhou,China;Department of Entomology and BIO5 Institute,University of Arizona,Tucson,AZ,USA;State Key Laboratory of Agricultural Microbiology,Huazhong Agricultural University,Wuhan,China;College of Science,Huazhong Agricultural University,Wuhan,China;USDA-ARS,Crop Genetics and Breeding Research Unit,University of Georgia,Tifton Campus,Tifton,GA,USA

中国昆虫科学（英文版）

[1]Zhongyuan Deng;Yuting Zhang;Chao Gao;Wei Shen;Shan Wang;Xinzhi Ni;Sisi Liu;Xianchun Li-.A transposon-introduced G-quadruplex motif is selectively retained and constrained to downregulate CYP321A1)[J].中国昆虫科学（英文版）,2022(06):1629-1642

CYP321A1,monooxygenases,zea,polyphagous,HzISl,HzIS1,silencer,allelochemicals,xanthotoxin,methylmesoporphyrin

introduced,selectively,retained,constrained,downregulate,Insects,utilize,compounds,cytochrome,P450s,involved,detoxification,toxic,xenobiotics,including,phytochemicals,pesticides,quadruplexes,G4,forming,motifs,are,enriched,promoter,regions,transcription,factors,function,cis,acting,elements,these,genes,Whether,gain,keep,their,expression,still,remain,unexplored,Here,we,show,that,metabolizing,from,Helicoverpa,insect,economic,importance,has,acquired,preserved,by,retaining,known,carries,this,its,acts,suppress,constitutive,induced,plant,flavone,through,folding,into,intramolecular,parallel,hybrid,conformation,absence,presence,K+,ligand,IX,NMM,strengthens,silencing,effect,switching,structure,enrichment,transposons,other,environment,adaptation,implies,retention,carrying,may,be,evolutionary,route,obtain

0.505072