Aldehyde dehydrogenase 3 converts farnesal into farnesoic acid in the corpora allata of mosquitoes

作者：Rivera Perez Crisalejandra; Nouzova Marcela; Clifton Mark E; Garcia Elena Martin; LeBlanc Elizabeth; Noriega Fernando G^*

来源：Insect Biochemistry and Molecular Biology, 2013, 43(8): 675-682.

DOI：10.1016/j.ibmb.2013.04.002

• Aedes aegypti
• Mosquito
• Juvenile hormone
• Corpora allata
• Aldehyde dehydrogenase 3
• RNAi
• Aldo-keto reductase
• Farnesal

The juvenile hormones (JHs) play a central role in insect reproduction, development and behavior. Interrupting JH biosynthesis has long been considered a promising strategy for the development of target-specific insecticides. Using a combination of RNAi, in vivo and in vitro studies we characterized the last unknown biosynthetic enzyme of the JH pathway, a fatty aldehyde dehydrogenase (AaALDH3) that oxidizes farnesal into farnesoic acid (FA) in the corpora allata (CA) of mosquitoes. The AaALDH3 is structurally and functionally a NAD(+)-dependent class 3 ALDH showing tissue- and developmental-stage-specific splice variants. Members of the ALDH3 family play critical roles in the development of cancer and Sjogren-Larsson syndrome in humans, but have not been studies in groups other than mammals. Using a newly developed assay utilizing fluorescent tags, we demonstrated that AaALDH3 activity, as well as the concentrations of famesol, famesal and FA were different in CA of sugar and blood-fed females. In CA of blood-fed females the low catalytic activity of AaALDH3 limited the flux of precursors and caused a remarkable increase in the pool of famesal with a decrease in FA and JH synthesis. The accumulation of the potentially toxic farnesal stimulated the activity of a reductase that converted famesal back into farnesol, resulting in farnesol leaking out of the CA. Our studies indicated AaALDH3 plays a key role in the regulation of JH synthesis in blood-fed females and mosquitoes seem to have developed a "trade-off" system to balance the key role of farnesal as a JH precursor with its potential toxicity. Published by Elsevier Ltd.

• 出版日期2013-8