title: Hexokinase is a key regulator of energy metabolism and ROS activity in insect lifespan extension.
abstract: Developmental arrest (diapause) is a 'non-aging' state that is similar to the Caenorhabditis elegans dauer stage and Drosophila lifespan extension. Diapause results in low metabolic activity and a profound extension of insect lifespan. Here, we cloned the Helicoverpa armigera Hexokinase (HK) gene, a gene that is critical for the developmental arrest of this species. HK expression and activity levels were significantly increased in nondiapause-destined pupae compared with those of diapause-destined pupae. Downregulation of HK activity reduced cell viability and delayed pupal development by reducing metabolic activity and increasing ROS activity, which suggests that HK is a key regulator of insect development. We then identified the transcription factors Har-CREB, -c-Myc, and -POU as specifically binding the Har-HK promoter and regulating its activity. Intriguingly, Har-POU and -c-Myc are specific transcription factors for HK expression, whereas Har-CREB is nonspecific. Furthermore, Har-POU and -c-Myc could respond to ecdysone, which is an upstream hormone. Therefore, low ecdysone levels in diapause-destined individuals lead to low Har-POU and -c-Myc expression levels, ultimately repressing Har-HK expression and inducing entry into diapause or lifespan extension.
authors: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510006, China.
authors: Xian-Wu
authors: XW
authors: Lin
authors: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510006, China.
authors: Wei-Hua
authors: WH
authors: Xu
mesh_terms: D000818:Animals; D015153:Blotting, Western; D047369:Chromatin Immunoprecipitation; D064666:Diapause, Insect / Q000502:physiology*; D024202:Electrophoretic Mobility Shift Assay; D004734:Energy Metabolism / Q000502:physiology*; D055785:Gene Knockdown Techniques; D006593:Hexokinase / Q000378:metabolism*; D019476:Insect Proteins / Q000502:physiology*; D008136:Longevity / Q000502:physiology; D009036:Moths / Q000502:physiology*; D011679:Pupa; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D019476:Insect Proteins; D006593:Hexokinase
keywords: Helicoverpa armigera; developmental arrest; gene regulation; hexokinase; transcription factor