SUCCINATE-DEHYDROGENASE-B MESSENGER-RNA OF DROSOPHILA-MELANOGASTER HAS A FUNCTIONAL IRON-RESPONSIVE ELEMENT IN ITS 5'-UNTRANSLATED REGION

Citation
Sa. Kohler et al., SUCCINATE-DEHYDROGENASE-B MESSENGER-RNA OF DROSOPHILA-MELANOGASTER HAS A FUNCTIONAL IRON-RESPONSIVE ELEMENT IN ITS 5'-UNTRANSLATED REGION, The Journal of biological chemistry, 270(51), 1995, pp. 30781-30786
Citations number
43
Categorie Soggetti
Biology
ISSN journal
00219258
Volume
270
Issue
51
Year of publication
1995
Pages
30781 - 30786
Database
ISI
SICI code
0021-9258(1995)270:51<30781:SMODH>2.0.ZU;2-O
Abstract
Iron-responsive elements (IREs) are cis-acting mRNA stem-loop structur es that specifically bind cytoplasmic iron regulatory proteins (IRPs), IRP-IRE interactions mediate the coordinate post transcriptional regu lation of key proteins in iron metabolism, such as ferritin, transferr in receptor, and erythroid 5-aminolevulinic acid synthase. Depending o n whether the IRE is located in the 5'- or 3'-untranslated region (UTR ), binding of IRP will inhibit mRNA translation or degradation, respec tively, Here we describe a new IRE in the 5'-UTR of succinate dehydrog enase subunit b (SDHb) mRNA of Drosophila melanogaster. The SDHb IRE b inds in vitro to vertebrate and insect IRPs with a high affinity equal to that of human ferritin H chain IRE. Under conditions of iron depri vation, SDHb mRNA of Drosophila SL-2 cells shifts to a non-polysome-bo und pool. Moreover, translation of a human growth hormone mRNA with th e SDHb IRE in its 5'-UTR is iron-dependent in stably transfected L cel ls, We conclude that the SDHb IRE mediates translational inhibition bo th in insect and vertebrate cells, This constitutes the first identifi cation of a functional IRE in insects. Furthermore, Drosophila SDHb re presents the second example, after porcine mitochondrial aconitase, of an enzyme of the citric acid cycle whose mRNA possesses all necessary features for translational regulation by cellular iron levels.