Juvenile hormones in insects are important for their growth before their adulthood, preventing metamorphosis if they undergo one. In Drosophila, only juvenile hormone III has been identified, while others exist in butterflies and moths. Synthesis of various forms of juvenile hormone III (JH III) start with farnesyl diphosphate interacting with an uncharacterized phosphatase protein, forming farnesol. Farnesol then interacts with NADP+ dependent farensol dehydrogenase, which removes a hydrogen ion from the hydroxyl group in order to form farnesal. Farnesal then enters the mitochondria and interacts with another uncharacterized aldehyde dehydrogenase which allows it to form farnesoic acid. Farnesoic acid can then interact with an unknown protein, similar to farnesoate epoxidase in Bombyx mori, in order to form juvenile hormone III acid (JH III acid). JH III acid can then interact with epoxide hydrolase in the membrane of the endoplasmic reticulum, forming the final product of this pathway, juvenile hormone III acid diol (JH III acid diol). It can also interact with juvenile hormone acid O-methyltransferase in order to form JH III, which is used in another set of reactions in this pathway. If farnesoic acid does not interact with the unknown protein, it may interact with juvenile hormone acid O-methyltransferase to form methyl farnesoate. Methyl farnesoate can then interact with a different unknown protein similar, to methyl farnesoate epoxidase in Diploptera punctata, in order to form JH III. In the mitochondria, JH III can interact with carboxylic ester hydrolase in order to form JH III acid, which then can form the final product, or form JH III again. Alternately, JH III can interact with epoxide hydrolase in the membrane of the endoplasmic reticulum, forming juvenile hormone III diol. This product then interacts with carboxylic ester hydrolase in the mitochondria, forming JH III acid diol, again, the end product of this pathway.

Juvenile Hormone Synthesis References