Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Dec 11:10.1111/1744-7917.13482.
doi: 10.1111/1744-7917.13482. Online ahead of print.

Juvenile hormone induces phosphorylation of insulin/insulin-like growth factor signaling proteins in previtellogenic Aedes aegypti mosquitoes

Wenhao Zhao  1 , Pengcheng Liu  1   2 , Thomas R Saunders  1 , Jinsong Zhu  1
Affiliations

Juvenile hormone induces phosphorylation of insulin/insulin-like growth factor signaling proteins in previtellogenic Aedes aegypti mosquitoes

Wenhao Zhao et al. Insect Sci. .

Abstract

Juvenile hormone (JH) plays a pivotal role in regulating post-emergence development and metabolism in previtellogenic female Aedes aegypti mosquitoes. In contrast, yolk protein precursor production and egg maturation after a blood meal are regulated by the steroid hormone 20-hydroxyecdysone, the insulin-like growth factor (IGF)/insulin signaling (IIS) pathway, and the mammalian target of rapamycin (mTOR) pathway. The role of IIS/mTOR signaling in female adults prior to blood feeding has not been thoroughly investigated. In this study, we identified a significant increase in the phosphorylation of key effector proteins in the IIS/mTOR signaling pathway, including eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), ribosomal protein S6 kinase (S6K) and forkhead box protein O1 (FoxO1), in previtellogenic females. In vitro fat body culture experiments suggest that JH induces these phosphorylations through rapid nongenomic signaling mediated by the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mTOR network. RNA interference experiments demonstrated that activation of IIS/mTOR signaling in previtellogenic females modulate metabolic gene expression, promoting the accumulation of energy reserves (glycogen and triglycerides), which influence mosquito fecundity. Additionally, depletion of either the insulin receptor (InR) or the JH receptor Methoprene-tolerant (Met) in adult mosquitoes abolished the phosphorylation of these proteins, indicating that both receptors are involved in JH-induced membrane-initiated signal transduction. Although the precise mechanisms remain unclear, this study uncovers a novel function of the IIS/mTOR pathway in adult mosquitoes before blood feeding, as well as a new mode of JH action through its crosstalk with the IIS pathway.

Keywords: RNAi; insulin signaling; juvenile hormone; mosquito; phosphorylation; reproduction.

PubMed Disclaimer

Conflict of interest statement

Disclosure

All authors declare no conflicts of interest.

References

    1. Ashok M, Turner C and Wilson TG (1998) Insect juvenile hormone resistance gene homology with the bHLH-PAS family of transcriptional regulators. Proceedings of the National Academy of Sciences USA, 95, 2761–2766. - PMC - PubMed
    1. Brown MR, Clark KD, Gulia M, Zhao Z, Garczynski SF, Crim JW, et al. (2008) An insulin-like peptide regulates egg maturation and metabolism in the mosquito Aedes aegypti. Proceedings of the National Academy of Sciences USA, 105, 5716–5721. - PMC - PubMed
    1. Charles JP, Iwema T, Epa VC, Takaki K, Rynes J and Jindra M (2011) Ligand-binding properties of a juvenile hormone receptor, Methoprene-tolerant. Proceedings of the National Academy of Sciences USA, 108, 21128–21133. - PMC - PubMed
    1. Clements AN (1992) The Biology of Mosquitoes. Chapman & Hall, London, UK. pp. 193–194.
    1. Clifton ME and Noriega FG (2012) The fate of follicles after a blood meal is dependent on previtellogenic nutrition and juvenile hormone in Aedes aegypti. Journal of Insect Physiology, 58, 1007–1019. - PMC - PubMed

LinkOut - more resources