Regulatory Functions of Nilaparvata lugens GSK-3 in Energy and Chitin Metabolism

Abstract

Glucose metabolism is a biologically important metabolic process. Glycogen synthase kinase (GSK-3) is a key enzyme located in the middle of the sugar metabolism pathway that can regulate the energy metabolism process in the body through insulin signaling. This paper mainly explores the regulatory effect of glycogen synthase kinase on the metabolism of glycogen and trehalose in the brown planthopper (Nilaparvata lugens) by RNA interference. In this paper, microinjection of the target double-stranded GSK-3 (dsGSK-3) effectively inhibited the expression of target genes in N. lugens. GSK-3 gene silencing can effectively inhibit the expression of target genes (glycogen phosphorylase gene, glycogen synthase gene, trehalose-6-phosphate synthase 1 gene, and trehalose-6-phosphate synthase 2 gene) in N. lugens and trehalase activity, thereby reducing glycogen and glucose content, increasing trehalose content, and regulating insect trehalose balance. GSK-3 can regulate the genes chitin synthase gene and glucose-6-phosphate isomerase gene involved in the chitin biosynthetic pathway of N. lugens. GSK-3 gene silencing can inhibit the synthesis of chitin N. lugens, resulting in abnormal phenotypes and increased mortality. These results indicated that a low expression of GSK-3 in N. lugens can regulate the metabolism of glycogen and trehalose through the insulin signal pathway and energy metabolism pathway, and can regulate the biosynthesis of chitin, which affects molting and wing formation. The relevant research results will help us to more comprehensively explore the molecular mechanism of the regulation of energy and chitin metabolism of insect glycogen synthase kinases in species such as N. lugens.

Muscle Glycogen Phosphorylase and Its Functional Partners in Health and Disease

“…The main function of PYGM and PYGB is their participation in adenosine triphosphate (ATP) production, gained from the glycogen deposits, to provide sufficient energy for biological processes in cells, such as contraction in the case of muscle. PYGL produces glucose molecules to maintain the glucose level in the bloodstream [ 5 , 10 , 11 , 12 ].…”

Silencing of Glycogen Synthase Kinase 3 Significantly Inhibits Chitin and Fatty Acid Metabolism in Asian Citrus Psyllid, Diaphorina citri

“…By silencing DcGSK3 , the D. citri molting from a fifth-instar nymph to an adult was significantly disrupted. According to Ding et al, the knockdown of GSK3 significantly affected the molting and wing formation of N. lugens [ 20 ].…”

“…GSK3 can inhibit glycogen synthase in insects by phosphorylating and blocking the transmission of the insulin signaling pathway [ 19 ]. Ding et al revealed that GSK3 is a key enzyme that regulates energy and chitin metabolism in N. lugens [ 20 ]. However, the molecular mechanisms by which GSK3 regulates chitin and fatty acid metabolism in D. citri have not yet been reported.…”

The diverse roles of insulin signaling in insect behavior

“…However, in the brown planthopper ( Nilaparvata lugens ), this pattern is generally reversed ( 31 , 124 ). Downstream mechanisms could include GSK3, which is associated with wing deformities ( 125 , 126 ). Wing tissues are particularly sensitive to ILPs and variation in IIS does not affect allometry or growth in other tissues ( 121 ).…”