title: Methoprene-tolerant 1 regulates gene transcription to maintain insect larval status.
abstract: Insect molting and metamorphosis are regulated by two hormones: 20-hydroxyecdysone (20E) and juvenile hormone (JH). The hormone 20E regulates gene transcription via the nuclear receptor EcR to promote metamorphosis, whereas JH regulates gene transcription via its intracellular receptor methoprene-tolerant (Met) to prevent larval-pupal transition. However, the function and mechanism of Met in various insect developments are not well understood. We propose that Met1 plays a key role in maintaining larval status not only by promoting JH-responsive gene transcription but also by repressing 20E-responsive gene transcription in the Lepidopteran insect Helicoverpa armigera. Met1 protein is increased during feeding stage and decreased during molting and metamorphic stages. Met1 is upregulated by JH III and a low concentration of 20E independently, but is downregulated by a high concentration of 20E. Knockdown of Met1 in larvae causes precocious pupation, decrease in JH pathway gene expression, and increase in 20E pathway gene expression. Met1 interacts with heat shock protein 90 and binds to JH response element to regulate Krüppel homolog 1 transcription in JH III induction. Met1 interacts with ultraspiracle protein 1 (USP1) to repress 20E transcription complex EcRB1/USP1 formation and binding to ecdysone response element. These data indicate that JH via Met1 regulates JH pathway gene expression and represses 20E pathway gene expression to maintain the larval status.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm InnovationMinistry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Zhao
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm InnovationMinistry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Liu
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm InnovationMinistry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm InnovationMinistry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Di
authors.initials: D
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm InnovationMinistry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Jin-Xing
authors.initials: JX
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm InnovationMinistry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China xfzhao@sdu.edu.cn.
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D004441:Ecdysterone / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D017344:Genes, Insect; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D019476:Insect Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D007605:Juvenile Hormones / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008675:Metamorphosis, Biological; D008726:Methoprene / Q000378:metabolism*; D008969:Molecular Sequence Data; D018978:Molting; D009036:Moths / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D020218:Response Elements; D015398:Signal Transduction; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D018841:HSP90 Heat-Shock Proteins; D019476:Insect Proteins; D007605:Juvenile Hormones; D004441:Ecdysterone; D008726:Methoprene
keywords: 20-hydroxyecdysone; gene transcription; juvenile hormone; methoprene-tolerant 1