Abstract
The synthesis of both transferrin receptor (TfR) and ferritin is regulated post-transcriptionally by iron. This is mediated by iron responsive elements (IREs) in the 5'- and 3'-untranslated regions, respectively, of TfR and ferritin mRNAs. Although these IREs have different sequences, they both form a characteristic stem-loop. We used competition assays and partial peptide mapping of UV-crosslinked ferritin and TfR IRE-protein complexes to show that the cytosolic protein binding to the ferritin 5'-IRE, the iron-responsive element binding protein (IRE-BP), also binds to TfR 3'-IREs. To identify the structural requirements necessary for RNA-protein binding, ferritin IRE RNAs were synthesized which contained altered secondary structures and base substitutions. Affinities of these RNAs for IRE-BP were assayed in RNA-protein binding gels. Substitutions disrupting base-pairing of the stem prevented IRE-BP binding. Substitutions which restored base-pairing also restored IRE-BP binding. We conclude that the IRE-BP binds to both ferritin and TfR IREs and recognizes a particular IRE conformation.
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- Aziz N., Munro H. N. Both subunits of rat liver ferritin are regulated at a translational level by iron induction. Nucleic Acids Res. 1986 Jan 24;14(2):915–927. doi: 10.1093/nar/14.2.915. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Aziz N., Munro H. N. Iron regulates ferritin mRNA translation through a segment of its 5' untranslated region. Proc Natl Acad Sci U S A. 1987 Dec;84(23):8478–8482. doi: 10.1073/pnas.84.23.8478. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown P. H., Daniels-McQueen S., Walden W. E., Patino M. M., Gaffield L., Bielser D., Thach R. E. Requirements for the translational repression of ferritin transcripts in wheat germ extracts by a 90-kDa protein from rabbit liver. J Biol Chem. 1989 Aug 15;264(23):13383–13386. [PubMed] [Google Scholar]
- Casey J. L., Hentze M. W., Koeller D. M., Caughman S. W., Rouault T. A., Klausner R. D., Harford J. B. Iron-responsive elements: regulatory RNA sequences that control mRNA levels and translation. Science. 1988 May 13;240(4854):924–928. doi: 10.1126/science.2452485. [DOI] [PubMed] [Google Scholar]
- Casey J. L., Koeller D. M., Ramin V. C., Klausner R. D., Harford J. B. Iron regulation of transferrin receptor mRNA levels requires iron-responsive elements and a rapid turnover determinant in the 3' untranslated region of the mRNA. EMBO J. 1989 Dec 1;8(12):3693–3699. doi: 10.1002/j.1460-2075.1989.tb08544.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cleveland D. W., Fischer S. G., Kirschner M. W., Laemmli U. K. Peptide mapping by limited proteolysis in sodium dodecyl sulfate and analysis by gel electrophoresis. J Biol Chem. 1977 Feb 10;252(3):1102–1106. [PubMed] [Google Scholar]
- Dautry-Varsat A., Ciechanover A., Lodish H. F. pH and the recycling of transferrin during receptor-mediated endocytosis. Proc Natl Acad Sci U S A. 1983 Apr;80(8):2258–2262. doi: 10.1073/pnas.80.8.2258. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dignam J. D., Lebovitz R. M., Roeder R. G. Accurate transcription initiation by RNA polymerase II in a soluble extract from isolated mammalian nuclei. Nucleic Acids Res. 1983 Mar 11;11(5):1475–1489. doi: 10.1093/nar/11.5.1475. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Haile D. J., Hentze M. W., Rouault T. A., Harford J. B., Klausner R. D. Regulation of interaction of the iron-responsive element binding protein with iron-responsive RNA elements. Mol Cell Biol. 1989 Nov;9(11):5055–5061. doi: 10.1128/mcb.9.11.5055. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hentze M. W., Rouault T. A., Harford J. B., Klausner R. D. Oxidation-reduction and the molecular mechanism of a regulatory RNA-protein interaction. Science. 1989 Apr 21;244(4902):357–359. doi: 10.1126/science.2711187. [DOI] [PubMed] [Google Scholar]
- Hunt T. Controlling mRNA lifespan. Nature. 1988 Aug 18;334(6183):567–568. doi: 10.1038/334567a0. [DOI] [PubMed] [Google Scholar]
- Klausner R. D., Ashwell G., van Renswoude J., Harford J. B., Bridges K. R. Binding of apotransferrin to K562 cells: explanation of the transferrin cycle. Proc Natl Acad Sci U S A. 1983 Apr;80(8):2263–2266. doi: 10.1073/pnas.80.8.2263. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Leibold E. A., Munro H. N. Characterization and evolution of the expressed rat ferritin light subunit gene and its pseudogene family. Conservation of sequences within noncoding regions of ferritin genes. J Biol Chem. 1987 May 25;262(15):7335–7341. [PubMed] [Google Scholar]
- Leibold E. A., Munro H. N. Cytoplasmic protein binds in vitro to a highly conserved sequence in the 5' untranslated region of ferritin heavy- and light-subunit mRNAs. Proc Natl Acad Sci U S A. 1988 Apr;85(7):2171–2175. doi: 10.1073/pnas.85.7.2171. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Milligan J. F., Groebe D. R., Witherell G. W., Uhlenbeck O. C. Oligoribonucleotide synthesis using T7 RNA polymerase and synthetic DNA templates. Nucleic Acids Res. 1987 Nov 11;15(21):8783–8798. doi: 10.1093/nar/15.21.8783. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Müllner E. W., Kühn L. C. A stem-loop in the 3' untranslated region mediates iron-dependent regulation of transferrin receptor mRNA stability in the cytoplasm. Cell. 1988 Jun 3;53(5):815–825. doi: 10.1016/0092-8674(88)90098-0. [DOI] [PubMed] [Google Scholar]
- Müllner E. W., Neupert B., Kühn L. C. A specific mRNA binding factor regulates the iron-dependent stability of cytoplasmic transferrin receptor mRNA. Cell. 1989 Jul 28;58(2):373–382. doi: 10.1016/0092-8674(89)90851-9. [DOI] [PubMed] [Google Scholar]
- Owen D., Kühn L. C. Noncoding 3' sequences of the transferrin receptor gene are required for mRNA regulation by iron. EMBO J. 1987 May;6(5):1287–1293. doi: 10.1002/j.1460-2075.1987.tb02366.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rogers J., Munro H. Translation of ferritin light and heavy subunit mRNAs is regulated by intracellular chelatable iron levels in rat hepatoma cells. Proc Natl Acad Sci U S A. 1987 Apr;84(8):2277–2281. doi: 10.1073/pnas.84.8.2277. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Romaniuk P. J., Lowary P., Wu H. N., Stormo G., Uhlenbeck O. C. RNA binding site of R17 coat protein. Biochemistry. 1987 Mar 24;26(6):1563–1568. doi: 10.1021/bi00380a011. [DOI] [PubMed] [Google Scholar]
- Rouault T. A., Hentze M. W., Caughman S. W., Harford J. B., Klausner R. D. Binding of a cytosolic protein to the iron-responsive element of human ferritin messenger RNA. Science. 1988 Sep 2;241(4870):1207–1210. doi: 10.1126/science.3413484. [DOI] [PubMed] [Google Scholar]
- Rouault T. A., Hentze M. W., Haile D. J., Harford J. B., Klausner R. D. The iron-responsive element binding protein: a method for the affinity purification of a regulatory RNA-binding protein. Proc Natl Acad Sci U S A. 1989 Aug;86(15):5768–5772. doi: 10.1073/pnas.86.15.5768. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tang C. K., Draper D. E. Unusual mRNA pseudoknot structure is recognized by a protein translational repressor. Cell. 1989 May 19;57(4):531–536. doi: 10.1016/0092-8674(89)90123-2. [DOI] [PubMed] [Google Scholar]
- Theil E. C. Ferritin: structure, gene regulation, and cellular function in animals, plants, and microorganisms. Annu Rev Biochem. 1987;56:289–315. doi: 10.1146/annurev.bi.56.070187.001445. [DOI] [PubMed] [Google Scholar]
- Walden W. E., Daniels-McQueen S., Brown P. H., Gaffield L., Russell D. A., Bielser D., Bailey L. C., Thach R. E. Translational repression in eukaryotes: partial purification and characterization of a repressor of ferritin mRNA translation. Proc Natl Acad Sci U S A. 1988 Dec;85(24):9503–9507. doi: 10.1073/pnas.85.24.9503. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Walden W. E., Patino M. M., Gaffield L. Purification of a specific repressor of ferritin mRNA translation from rabbit liver. J Biol Chem. 1989 Aug 15;264(23):13765–13769. [PubMed] [Google Scholar]
- Zähringer J., Baliga B. S., Munro H. N. Novel mechanism for translational control in regulation of ferritin synthesis by iron. Proc Natl Acad Sci U S A. 1976 Mar;73(3):857–861. doi: 10.1073/pnas.73.3.857. [DOI] [PMC free article] [PubMed] [Google Scholar]