title: The steroid hormone 20-hydroxyecdysone upregulated the protein phosphatase 6 for the programmed cell death in the insect midgut.
abstract: Programmed cell death (PCD) plays an important role in insect midgut remodeling during metamorphosis. Insect midgut PCD is triggered by the steroid hormone 20-hydroxyecdysone (20E) and it is mediated by a series of genes. However, the mechanism by which 20E triggers midgut PCD is still unclear. Here, we report a protein phosphatase 6 (PP6) from Helicoverpa armigera playing roles in midgut PCD. PP6 was expressed in the midgut during larval growth and it is significantly increased during metamorphosis. The increase was proven to be regulated by 20E. The juvenile hormone analog methoprene has no effect on PP6 expression. RNA interference analysis suggests that 20E upregulated the PP6 transcript levels through the ecdysone receptor EcRB1. PP6 knockdown by larval feeding or PP6 dsRNA injection resulted in the repression of the midgut PCD during the metamorphic stage. The mechanism was demonstrated to be through the suppression of genes such as Broad (Br), E74a, E75b, HR3, E93, rpr, and caspase, which are involved in 20E signaling pathway or midgut PCD. These findings suggest that PP6 is involved in the 20E signal transduction pathway and participates in the PCD in midgut.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, Shandong, China.
authors.forename: Chuan-Xu
authors.initials: CX
authors.lastname: Wang
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Zheng
authors.forename: Peng-Cheng
authors.initials: PC
authors.lastname: Liu
authors.forename: Jin-Xing
authors.initials: JX
authors.lastname: Wang
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Zhao
mesh_terms: D000818:Animals; D016923:Cell Death; D004441:Ecdysterone / Q000494:pharmacology / Q000502:physiology; D005216:Fat Body / Q000201:enzymology / Q000254:growth & development; D041981:Gastrointestinal Tract / Q000166:cytology* / Q000201:enzymology / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D006434:Hemocytes / Q000201:enzymology; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D007814:Larva / Q000166:cytology / Q000201:enzymology / Q000254:growth & development; D008675:Metamorphosis, Biological; D008969:Molecular Sequence Data; D009036:Moths / Q000166:cytology / Q000201:enzymology* / Q000254:growth & development; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D011987:Receptors, Steroid / Q000378:metabolism; D015398:Signal Transduction; D014158:Transcription, Genetic
chemical_list: D019476:Insect Proteins; D011987:Receptors, Steroid; D004441:Ecdysterone; D010749:Phosphoprotein Phosphatases; C106079:protein phosphatase 6