Manduca sexta IRP1: molecular characterization and in vivo response to iron
Document Type
Article
Publication Date
2001
Abstract
Manduca sexta IRP1 was cloned and sequenced. The deduced amino acid sequence of Manduca IRP1 shows high similarity to other IRP1 proteins. The Cys residues required as ligands for the iron sulfur cluster, as well as all residues necessary for aconitase activity are conserved in the insect protein. Purified recombinant Manduca IRP1 binds specifically to transcripts of the iron responsive element (IRE) of Manduca or human ferritin subunit mRNA. Binding activity of the recombinant protein was not influenced by the presence of β-mercaptoethanol. However, IRP/IRE binding activity of cytoplasmic extracts from fat body was decreased by reducing agents in a dose-responsive manner. Fat body IRP1/IRE binding activity was reduced for Manduca sexta larvae injected with low doses of iron, while IRP1 mRNA and protein levels remained stable. At higher iron doses, binding activity increased and stabilized. Hemolymph ferritin levels showed an inverse relationship to IRP1/IRE binding activity. These data suggest that the Manduca IRP1 is likely involved in translational control of ferritin synthesis in a manner similar to that found in vertebrates. However, factors other than iron can influence IRP/IRE interaction and hemolymph ferritin levels in insects.
Publication Title
Insect biochemistry and molecular biology
Volume
32
Issue
1
First Page
85
Last Page
96
Recommended Citation
Zhang, Dianzheng; Ferris, Cara; Gailer, Jurgen; Kohlhepp, Pete; and Winzerling, Joy J., "Manduca sexta IRP1: molecular characterization and in vivo response to iron" (2001). PCOM Scholarly Works. 382.
https://digitalcommons.pcom.edu/scholarly_papers/382
Comments
This article was published in Insect biochemistry and molecular biology, Volume 32, Issue 1, Pages 85-96.
The published version is available at http://dx.doi.org/10.1016/S0965-1748(01)00083-2.Copyright © 2001 Elsevier.