Prostaglandins influence protein phosphorylation in established insect cell lines

Authors: Stanley, David; Goodman, Cynthia; Ringbauer, Joseph - Joe; SONG, QISHENG - University Of Missouri

Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/3/2020
Publication Date: 7/18/2020
Citation: Stanley, D.W., Goodman, C.L., Ringbauer Jr, J.A., Song, Q. 2020. Prostaglandins influence protein phosphorylation in established insect cell lines. Archives of Insect Biochemistry and Physiology. 105(1). Article 21725. https://doi.org/10.1002/arch.21725.
DOI: https://doi.org/10.1002/arch.21725

Interpretive Summary: Some insect species are devastating pests of human and animal food crops. These pests are managed to some extent by application of chemical insect killers, although there are serious problems associated with use of such agricultural chemicals. One alternative to chemical insect management is biological control of insect pests, which involves application of natural enemies, such as predators, parasites and insect-specific bacteria. While biological control programs are effective in some cropping systems, they have not yet reached their full potential because pest insects have natural defenses against biological control agents. We are working to understand biochemical signals that operate within pest insects to defend themselves against natural enemies. These signals have potential as specific targets that may be exploited to breakdown pest insect defenses against biological control agents. In this paper, we report on identification of new biochemical signals. This new information will be used by scientists at the global working to improving biological control technologies. Ultimately, improved biological control technologies will lead to increased food and nutritional security while reducing the negative impacts of agricultural chemicals.

Technical Abstract: rostaglandins (PGs) are oxygenated metabolites of arachidonic acid and two other C20 polyunsaturated fatty acids. Among other actions in invertebrates, PGs act in ovarian development, renal functions, immunity, hemocyte migration and gene/protein expression. Reversible phosphorylation is a major mechanism of regulating protein functions in eukaryotic cells and for some mammalian proteins it is influenced by PGs. We posed the hypothesis that PGs influence protein phosphorylation within insect cells, which we tested with the established insect cell line, BCIRL-HzAM1. After 20, 30 or 40 min incubations in the presence of one of three PGs (at 15 microM), PGA2, PGE1 or PGF2a, separate sets of cells were processed for analysis by 2D-electrophoresis (followed by MS/MS). We recorded significant phosphorylation changes in 31 proteins, decreases in 15 and increases in 15, and one protein with increased or decreased phosphorylation, depending on PG treatment. Increasing PG exposure times led to changes in fewer proteins, 20 min incubations led to changes in 16 proteins, 30 min to changes in 13 and 40 min to changes in two proteins. The proteins were identified by bioinformatic analyses, including transcript description, calculated molecular weights and pIs, MOWSE score, total ion score, numbers of peptides, percent protein coverage, E-value, and highest peptide score. The data presented in this paper firmly support our hypothesis that PGs influence protein phosphorylation within insect cells and adds a novel PG-signaled function to insect biology.