The juvenile hormone (JH) epoxide hydrolase gene in the honey bee (Apis mellifera) genome encodes a protein which has negligible participation in JH degradation.
Epoxide hydrolases are multifunctional enzymes that are best known in insects for their role in juvenile hormone (JH) degradation. Enzymes involved in JH catabolism can play major roles during metamorphosis and reproduction, such as the JH epoxide hydrolase (JHEH), which degrades JH through hydration of the epoxide moiety to form JH diol, and JH esterase (JHE), which hydrolyzes the methyl ester to produce JH acid. In the honey bee, JH has been co-opted for additional functions, mainly in caste differentiation and in age-related behavioral development of workers, where the activity of both enzymes could be important for JH titer regulation. Similarity searches for jheh candidate genes in the honey bee genome revealed a single Amjheh gene. Sequence analysis, quantification of Amjheh transcript levels and Western blot assays using an AmJHEH-specific antibody generated during this study revealed that the AmJHEH found in the fat body shares features with the microsomal JHEHs from several insect species. Using a partition assay we demonstrated that AmJHEH has a negligible role in JH degradation, which, in the honey bee, is thus performed primarily by JHE. High AmJHEH levels in larvae and adults were related to the ingestion of high loads of lipids, suggesting that AmJHEH has a role in dietary lipid catabolism.
Mackert
Aline
A
Departamento de Ciências do Ambiente, Campus do Pantanal, Universidade Federal do Mato Grosso do Sul, Mato Grosso do Sul, Brazil. mackert@rge.fmrp.usp.br
Hartfelder
Klaus
K
Bitondi
Márcia Maria Gentile
MM
Simões
Zilá Luz Paulino
ZL
D000818:Animals; D001483:Base Sequence; D001516:Bees / Q000201:enzymology*; D015153:Blotting, Western; D001938:Brazil; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics; D004032:Diet; D004851:Epoxide Hydrolases / Q000235:genetics*; D005216:Fat Body / Q000378:metabolism; D007605:Juvenile Hormones / Q000378:metabolism*; D050356:Lipid Metabolism; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013045:Species Specificity
D017931:DNA Primers; D007605:Juvenile Hormones; D002265:Carboxylic Ester Hydrolases; C038003:juvenile hormone esterase; D004851:Epoxide Hydrolases; C055698:juvenile hormone epoxide hydrolase