Cloning and molecular characterization of two mosquito iron regulatory proteins
Autor(es): Zhang, D; Dimopoulos, G; Wolf, A; Minana, B; Kafatos, FC; Winzerling, JJ
Resumo: Iron regulatory proteins (IRPs) control the synthesis of various proteins at the translational level by binding to iron responsive elements (IREs) in the mRNAs. Iron, infection, and stress can alter IRP/IRE binding activity. Insect messenger RNAs for ferritin and succinate dehydrogenase subunit b have IREs that are active translational control sites. We have cloned and sequenced cDNAs encoding proteins from the IRP1 family for the mosquitoes, Aedes aegypti and Anopheles gambiae. Both deduced amino acid sequences show substantial similarity to human IRP1 and Drosophila IRP1A and IRP1B, and all of the residues thought to be involved in aconitase activity and iron-sulfur cluster formation are conserved. Recombinant A. aegypti IRP1 binds to transcripts of the IREs of mosquito or human ferritin subunit mRNAs. No significant change in A. gambiae IRPI messenger RNA could be detected during the various developmental stages of the life cycle, following iron loading by blood feeding, or after bacterial or parasitic infections. These data suggest that there is no change in gene transcription. Furthermore, bacterial challenge of A. gambiae cells did not change IRPI protein levels. In contrast, IRPI binding activity for the IRE was elevated following immune induction. These data show that changes in IRP1/IRE binding activity occur as part of the insect immune response. (C) 2002 Elsevier Science Ltd. All rights reserved.
Palavras-Chave: Iron; Iron regulatory protein; Mosquitoes; Infection
Imprenta: Insect Biochemistry and Molecular Biology, v. 32, n. 5, p. 579-589, 2002
Identificador do objeto digital: 10.1016/S0965-1748(01)00138-2
Descritores: Aedes aegypti - DNA ; Aedes aegypti - Immune response ; Aedes aegypti - Molecular structure ; Aedes aegypti - Protein synthesis ; Aedes aegypti - RNA
Data de publicação: 2002
