Functional expression and characterization of CAPA receptor in the digestive tract and life stages of Drosophila suzukii, and differential activities with insect PRXamide peptides

Authors: Price, Briana; JANG, HYO SANG - Oregon State University; PARKS, RYSSA - Oregon State University; Choi, Man-Yeon

Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2023
Publication Date: 8/16/2024
Citation: Price, B.E., Jang, H., Parks, R., Choi, M.Y. 2024. Functional expression and characterization of CAPA receptor in the digestive tract and life stages of Drosophila suzukii, and differential activities with insect PRXamide peptides. Archives of Insect Biochemistry and Physiology. 116(4):e22080. https://doi.org/10.1002/arch.22080.
DOI: https://doi.org/10.1002/arch.22080

Interpretive Summary: Spotted-wing drosophila (SWD), Drosophila suzukii, is an invasive vinegar fly that is a major threat to the small fruits and cherries industries globally. The primary control methods for SWD rely on conventional insecticides, mostly chemical applications. A recent research approach has sought to develop chemical alternatives focused on biologically based control methods. This study identified and characterized a neuropeptide (= short protein molecules produced in nerve tissues, i.e., brain) and its receptor from SWD – the neuropeptide name is CAPA. CAPA peptide and its receptor are involved in various biological functions in insects, including diuresis, anti-diuresis, and renal modulation (= similar to the kidney work in mammals). We tested 36 bioactive peptides, including the CAPA peptide, and evaluated insecticidal effects on SWD survival. The results will be used to develop new SWD controls in the field.

Technical Abstract: Insect capa genes encode multiple neuropeptides, including CAPA-periviscerokinin (CAPA-PVK) peptides that specifically are known to cause diuresis or anti-diuresis in some organisms. Here we identified and characterized a corresponding G protein-coupled receptor (GPCR) to the D. suzukii CAPA-PVK peptides, CAPA receptor (CAPA-R). In insect cell-based functional expression assays, we evaluated responses of CAPA-R to D. suzukii CAPA-PVKs, CAPA-PVKs from five species in Insecta, one species from Mollusca, modified CAPA-PVK peptides, and some PRXamide family peptides, such as pyrokinin (PK), diapause hormone (DH), and ecdysis-triggering hormone (ETH) peptides to better characterize the behavior of D. suzukii CAPA-R. Functional studies revealed that the D. suzukii CAPA-R is strongly activated both of its own natural D. suzukii CAPA-PVKs, and interestingly, it was strongly activated by other CAPA-PVK peptides from Frankliniella occidentallis (Thysanoptera), Solenopsis invicta (Hymenoptera), Helicoverpa zea, and Plutella xylostella (Lepidoptera). However, D. suzukii CAPA-R was not activated by Mollusca CAPA-PVK or the other PRXamide peptides. The CAPA-R was highly expressed in the Malpighian tubules, compared to other digestive organs or the rest of body, which is supportive of diuretic/antidiuretic functionality. When compared across life stages of D. suzukii, expression of CAPA-R was approximately 1.5x greater in the 3rd instar than the other stages and minimally detected in the eggs, 4-day old pupae and 3-day old adults. These results foundationally characterized the D. suzukii CAPA-R, and the short peptides identified using the CAPA-R help in the development of biological targets for this species.