Journal
INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY
Volume 32, Issue 8, Pages 829-837Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/S0965-1748(01)00145-X
Keywords
ecdysone; molting; immune response; aldo-keto reductase
Categories
Ask authors/readers for more resources
During the screening of immune-regulated genes from the cabbage looper, Trichoplusia ni, a 3-dehydroecdysone 3beta-reductase homologue (DERH) was cloned. In the course of development, 3-dehydroecdysone 3beta-reductase mediates the conversion of 3-dehydroecdysone (3dE) secreted from the prothoracic glands to ecdysone (E), which is subsequently converted to 20-hydroxyecdysone (20E), the major insect molting hormone. The cloned gene is upregulated in fat body during development and is strongly induced after the larva is challenged with bacteria. The gene codes for a 308 amino acid residue protein which shows 42.5%. identity to Spodoptera littoralis 3-dehydroecdysone 3beta-reductase. Using the baculovirus expression system, the recombinant DERH was expressed. The purified protein mediates the reduction of 3-dehydromakisterone A to makisterone A, and requires NADPH as a cofactor. Western blots using an antiserum to T. ni DERH revealed the presence of the protein in larval hemolymph and integument. The data indicate that the protein is regulated developmentally and is induced after a challenge with bacteria. Immunohistochemical studies localized the enzyme exclusively in the epidermis and the cuticle. (C) 2002 Elsevier Science Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available