Analysis of a juvenile hormone esterase binding protein
Juvenile hormone esterase (JHE) helps to regulate the titer of juvenile hormone and, hence, larval development in insects. JHE is cleared from the hemolymph by athrocytes via receptor-mediated endocytosis, and is degraded in lysosomes. We investigated the role of a putative 29 kDa JHE binding protein (P29) in relation to the biology of JHE. We worked with both the tobacco hornworm Manduca sexta, and the fruit fly Drosophila melanogaster as model systems for the study of P29. Disruption of the intracellular trafficking of JHE has potential as a target for development of novel insecticides.
We established that overexpression in Drosophila melanogaster of the JHE binding protein, DmP29 results in a series of apparent anti-JH effects (Liu et al., 2008). Overexpression of DmP29 during the first or second instar was lethal, while overexpression during the third instar resulted in eclosion of small adults. Overexpression of DmP29 in newly eclosed flies reduced ovarian development and fecundity in addition to reducing the abundance of aggregation pheromone in males and courtship pheromone in females. Females exhibited reduced receptivity to mating, and males exhibited male-male courtship behavior, with both sexes being hyperactive.
Watch the videos (linked below) of hyperactivity and male-male courtship behavior in flies with overexpressed DmP29. Pheromones that normally inhibit male-male courtship interactions are absent in these flies. Note in the images and movies below, the extended wings (“singing”) associated with Drosophila courtship behavior, and lines of males each attempting to court the male in front.
Bonning, B.C., Ward, V.K., van Meer, M.M., Booth, T.F. and Hammock, B.D. 1997. Disruption of lysosomal targeting is associated with insecticidal potency of juvenile hormone esterase. Proceedings of the National Academy of Sciences USA 94 (12):6007-6012. [Full Text]
Bonning, B.C., Possee, R.D. and Hammock, B.D. 1999. Insecticidal efficacy of a recombinant baculovirus expressing JHE-KK, a modified juvenile hormone esterase. Journal of Invertebrate Pathology 73: 234-236.
Shanmugavelu, M., Baytan, A., Chesnut, J.D. and Bonning, B.C. 2000. A novel protein that binds juvenile hormone esterase in fat body and pericardial cells of the tobacco hornworm Manduca sexta L. Journal of Biological Chemistry 275(3): 1802-1806. [Full Text]
Shanmugavelu, M., Larysa Porubleva, Parag Chitnis, and Bonning, B.C. 2001. Ligand blot analysis of juvenile hormone esterase binding proteins in Manduca sexta L. Insect Biochem. Molec. Biol. 31(1): 51-56. [Full Text]
Liu, Z., Ho, L., Bonning, B.C. 2007. Localization of a Drosophila melanogaster homolog of the putative juvenile hormone esterase binding protein of Manduca sexta. Insect Biochem. Molec. Biol. 37(2): 155-163.
Liu, Z., Pal, N., Bonning, B.C. 2007. Potential ligands of DmP29, a putative juvenile hormone esterase binding protein of Drosophila melanogaster. Insect Biochem Molec Biol 37: 838-846.
Liu Z, Li X, Prasifka JR, Jurenka R, Bonning BC. 2008. Overexpression of Drosophila juvenile hormone esterase binding protein results in anti-JH effects and reduced pheromone abundance. Gen. Comp. Endocrinol. 156: 164-172.
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