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Insect Biochemistry and Molecular... Jun 2023Juvenile hormone (JH) has a classic "status quo" action at both the pupal and adult molts when administrated exogenously. In Drosophila, treatment with JH at pupariation...
Juvenile hormone (JH) has a classic "status quo" action at both the pupal and adult molts when administrated exogenously. In Drosophila, treatment with JH at pupariation inhibits the formation of abdominal bristles, which are derived from the histoblasts. However, the mechanism via which JH exerts this effect remains poorly understood. In this study, we analyzed the effect of JH on histoblast proliferation, migration, and differentiation. Our results indicated that whereas the proliferation and migration of histoblasts remained unaffected following treatment with a JH mimic (JHM), their differentiation, particularly the specification of sensor organ precursor (SOP) cells, was inhibited. This effect was attributable to downregulated proneural genes achaete (ac) and Scute (sc) expression levels, which prevented the specification of SOP cells in proneural clusters. Moreover, Kr-h1 was found to mediate this effect of JHM. Histoblast-specific overexpression or knockdown of Kr-h1, respectively mimicked or attenuated the effects exerted by JHM on abdominal bristle formation, SOP determination, and transcriptional regulation of ac and sc. These results indicated that the defective SOP determination was responsible for the inhibition of abdominal bristle formation by JHM, which, in turn, was mainly mediated via the transducing action of Kr-h1.
Topics: Animals; Drosophila; Juvenile Hormones; Morphogenesis; Drosophila Proteins; Abdomen; Gene Expression Regulation, Developmental
PubMed: 37192726
DOI: 10.1016/j.ibmb.2023.103957 -
Science (New York, N.Y.) Mar 1973The substitution of a 7-alkoxy group for the 6,7-epoxy moiety in aryl terpenoid ethers having high juvenile hormone activity has produced several compounds exceptionally...
The substitution of a 7-alkoxy group for the 6,7-epoxy moiety in aryl terpenoid ethers having high juvenile hormone activity has produced several compounds exceptionally active against Tenebrio molitor. The most potent compound [7-ethoxy-1-(p-ethylphenoxy)-3,7-dimethyl-2-octene, called JH-25] is active at the level of 10 picograms per insect, or about 100 times more active than other promising juvenile hormone mimics so far reported. Compound JH-25 was also active against Tribolium confusum.
Topics: Biological Assay; Chemical Phenomena; Chemistry; Juvenile Hormones; Tenebrio; Tribolium
PubMed: 4687026
DOI: 10.1126/science.179.4080.1342 -
Annual Review of Biochemistry 1971
Review
Topics: Amines; Aniline Compounds; Animals; Behavior, Animal; Benzoates; Biological Assay; Bombyx; Carboxylic Acids; Chemical Phenomena; Chemistry; Chlorine; Cyclohexanecarboxylic Acids; Ethers; Ethers, Cyclic; Insecta; Insecticides; Juvenile Hormones; Larva; Metabolism; Metamorphosis, Biological; Models, Structural; Peptides; Pupa; Species Specificity; Stereoisomerism; Structure-Activity Relationship; Terpenes
PubMed: 4941234
DOI: 10.1146/annurev.bi.40.070171.005243 -
Journal of Insect Physiology Jul 2014In the polyandric moth, Spodopterafrugiperda, juvenile hormone (JH) is transferred from the male accessory reproductive glands (AG) to the female bursa copulatrix (BC)...
In the polyandric moth, Spodopterafrugiperda, juvenile hormone (JH) is transferred from the male accessory reproductive glands (AG) to the female bursa copulatrix (BC) during copulation (see Hassanien et al., 2014). Here we used the RNA interference technique to study the role of allatoregulating neuropeptides in controlling the synthesis and transfer of JH during mating. Knockdown of S. frugiperda allatostatin C (Spofr-AS type C) in freshly emerged males leads to an accumulation of JH in the AG beyond that in the control and mating results in a higher transport of JH I and JH II into the female BC. Knockdown of S. frugiperda allatotropin 2 (Spofr-AT2) significantly reduces the amount of JH in the AG as well as its transfer into the female BC during copulation. Knockdown of S. frugiperda allatostatin A (Spofr-AS type A) and S. frugiperda allatotropin (Spofr-AT; Hassanien et al., 2014) only slightly affects the accumulation of JH in the AG and its transfer from the male to the female. We conclude that Spofr-AS type C and Spofr-AT2 act as true allatostatin and true allatotropin, respectively, on the synthesis of JH I and JH II in the male AG. Moreover, both peptides seem to control the synthesis of JH III in the corpora allata of adult males and its release into the hemolymph.
Topics: Animals; Chromatography, Liquid; Female; Gene Knockdown Techniques; Insect Hormones; Juvenile Hormones; Male; Mass Spectrometry; Neuropeptides; RNA Interference; RNA, Double-Stranded; Sexual Behavior, Animal; Spodoptera
PubMed: 24852671
DOI: 10.1016/j.jinsphys.2014.05.012 -
Proceedings of the National Academy of... Nov 2022Juvenile hormones (JHs) control insect metamorphosis and reproduction. JHs act through a receptor complex consisting of methoprene-tolerant (Met) and taiman (Tai)...
Juvenile hormones (JHs) control insect metamorphosis and reproduction. JHs act through a receptor complex consisting of methoprene-tolerant (Met) and taiman (Tai) proteins to induce transcription of specific genes. Among chemically diverse synthetic JH mimics (juvenoids), some of which serve as insecticides, unique peptidic juvenoids stand out as being highly potent yet exquisitely selective to a specific family of true bugs. Their mode of action is unknown. Here we demonstrate that, like established JH receptor agonists, peptidic juvenoids act upon the JHR Met to halt metamorphosis in larvae of the linden bug, . Peptidic juvenoids induced ligand-dependent dimerization between Met and Tai proteins from but, consistent with their selectivity, not from other insects. A cell-based split-luciferase system revealed that the Met-Tai complex assembled within minutes of agonist presence. To explore the potential of juvenoid peptides, we synthesized 120 new derivatives and tested them in Met-Tai interaction assays. While many substituents led to loss of activity, improved derivatives active at sub-nanomolar range outperformed hitherto existing peptidic and classical juvenoids including fenoxycarb. Their potency in inducing Met-Tai interaction corresponded with the capacity to block metamorphosis in larvae and to stimulate oogenesis in reproductively arrested adult females. Molecular modeling demonstrated that the high potency correlates with high affinity. This is a result of malleability of the ligand-binding pocket of Met that allows larger peptidic ligands to maximize their contact surface. Our data establish peptidic juvenoids as highly potent and species-selective novel JHR agonists.
Topics: Animals; Female; Juvenile Hormones; Ligands; Methoprene; Insecta; Reproduction; Larva; Peptides
PubMed: 36409882
DOI: 10.1073/pnas.2215541119 -
Trends in Endocrinology and Metabolism:... 2005Two hormones, 20-hydroxyecdysone (20E) and juvenile hormone (JH), coordinately orchestrate insect growth and development. 20E initiates all major developmental... (Review)
Review
Two hormones, 20-hydroxyecdysone (20E) and juvenile hormone (JH), coordinately orchestrate insect growth and development. 20E initiates all major developmental transitions from egg, to larva, to pupa, to adult, but it is an interaction with the JH signal that transduces 20E pulses into stage-specific responses. Years of research have given us an understanding of 20E signaling pathway. By contrast, the molecular mechanism of JH action remains an enigma. Recent studies provide insight into the molecular background to JH-20E regulatory interplay. Two transcription factors--BR-C and E75A--contribute to the cross-talk between the two hormones. It appears that BR-C is a key target of JH status quo action, and E75A is a part of the mechanism whereby JH prevents BR-C activation.
Topics: Animals; Ecdysterone; Hormones; Insecta; Juvenile Hormones; Receptor Cross-Talk
PubMed: 15620543
DOI: 10.1016/j.tem.2004.11.003 -
Brazilian Journal of Medical and... Feb 2000Juvenile hormone (JH) exerts pleiotropic functions during insect life cycles. The regulation of JH biosynthesis by neuropeptides and biogenic amines, as well as the... (Review)
Review
Juvenile hormone (JH) exerts pleiotropic functions during insect life cycles. The regulation of JH biosynthesis by neuropeptides and biogenic amines, as well as the transport of JH by specific binding proteins is now well understood. In contrast, comprehending its mode of action on target organs is still hampered by the difficulties in isolating specific receptors. In concert with ecdysteroids, JH orchestrates molting and metamorphosis, and its modulatory function in molting processes has gained it the attribute "status quo" hormone. Whereas the metamorphic role of JH appears to have been widely conserved, its role in reproduction has been subject to many modifications. In many species, JH stimulates vitellogenin synthesis and uptake. In mosquitoes, however, this function has been transferred to ecdysteroids, and JH primes the ecdysteroid response of developing follicles. As reproduction includes a variety of specific behaviors, including migration and diapause, JH has come to function as a master regulator in insect reproduction. The peak of pleiotropy was definitely reached in insects exhibiting facultative polymorphisms. In wing-dimorphic crickets, differential activation of JH esterase determines wing length. The evolution of sociality in Isoptera and Hymenoptera has also extensively relied on JH. In primitively social wasps and bumble bees, JH integrates dominance position with reproductive status. In highly social insects, such as the honey bee, JH has lost its gonadotropic role and now regulates division of labor in the worker caste. Its metamorphic role has been extensively explored in the morphological differentiation of queens and workers, and in the generation of worker polymorphism, such as observed in ants.
Topics: Animals; Bees; Behavior, Animal; Female; Insecta; Juvenile Hormones; Male; Metamorphosis, Biological; Polymorphism, Genetic; Reproduction; Sex Characteristics
PubMed: 10657056
DOI: 10.1590/s0100-879x2000000200003 -
Pesticide Biochemistry and Physiology May 2023Juvenile hormone (JH) plays a crucial endocrine regulatory role in insect metamorphosis, reproduction, and longevity in multiple organisms, such as flies, honeybees, and...
Juvenile hormone (JH) plays a crucial endocrine regulatory role in insect metamorphosis, reproduction, and longevity in multiple organisms, such as flies, honeybees, and migratory monarch butterflies. However, the molecular mechanism of JH affecting longevity remains largely unknown. In this study, we showed that JH III and its analog methoprene shortened the survival days significantly in the adulthood of male silkworm. At the same time, the allatostatin, a neuropeptide that inhibits the secretion of JH by the corpora allata, could extend the survival days dramatically after adult eclosion in male silkmoth. Interestingly, a central pro-longevity FoxO transcription factor was reduced upon JH stimulation in silkworm individuals and BmN-SWU1 cells. Furthermore, the analysis of the upstream sequence of the FoxO gene identified a JH response element which suggested that FoxO might be regulated as a target of JH. Surprisingly, we identified a Bmtakeout (BmTO) gene that encodes a JH-binding protein and contains a FoxO response element. As expected, FoxO overexpression and knockdown up- and down-regulated the expression of BmTO respectively, indicating that BmTO functions as a FoxO target. BmTO overexpression could release the inhibitory effect of JH on the BmFoxO gene by reducing JH bioavailability to block its signal transduction. Collectively, these results may provide insights into the mechanism of the JH-FoxO-TO axis in aging research and pest control.
Topics: Animals; Juvenile Hormones; Bombyx; Longevity; Butterflies; Metamorphosis, Biological
PubMed: 37105617
DOI: 10.1016/j.pestbp.2023.105388 -
Nature Oct 1971
Topics: Amines; Animals; Cockroaches; Culex; Houseflies; Insecta; Juvenile Hormones; Pupa; Terpenes
PubMed: 4939546
DOI: 10.1038/233488a0 -
The Journal of Biological Chemistry Nov 2021Juvenile hormone (JH) acid methyltransferase (JHAMT) is a rate-limiting enzyme that converts JH acids or inactive precursors of JHs to active JHs at the final step of JH...
Juvenile hormone (JH) acid methyltransferase (JHAMT) is a rate-limiting enzyme that converts JH acids or inactive precursors of JHs to active JHs at the final step of JH biosynthesis in insects and thus presents an excellent target for the development of insect growth regulators or insecticides. However, the three-dimensional properties and catalytic mechanism of this enzyme are not known. Herein, we report the crystal structure of the JHAMT apoenzyme, the three-dimensional holoprotein in binary complex with its cofactor S-adenosyl-l-homocysteine, and the ternary complex with S-adenosyl-l-homocysteine and its substrate methyl farnesoate. These structures reveal the ultrafine definition of the binding patterns for JHAMT with its substrate/cofactor. Comparative structural analyses led to novel findings concerning the structural specificity of the progressive conformational changes required for binding interactions that are induced in the presence of cofactor and substrate. Importantly, structural and biochemical analyses enabled identification of one strictly conserved catalytic Gln/His pair within JHAMTs required for catalysis and further provide a molecular basis for substrate recognition and the catalytic mechanism of JHAMTs. These findings lay the foundation for the mechanistic understanding of JH biosynthesis by JHAMTs and provide a rational framework for the discovery and development of specific JHAMT inhibitors as insect growth regulators or insecticides.
Topics: Animals; Bombyx; Crystallography, X-Ray; Insect Proteins; Juvenile Hormones; Methyltransferases; Protein Domains
PubMed: 34562453
DOI: 10.1016/j.jbc.2021.101234