Summary
Iron stimulates ferritin synthesis in whole cells and animals, by increasing the entry of ferritin mRNA into polyribosomes. Dissection of the regulation at the molecular level has identified a 28-nucleotide, conserved, regulatory sequence (IRE=iron regulatory element) in the 5′ non-coding region of ferritin mRNAs, plustrans-acting factor(s), one of which is a 90-kDa protein. The site of iron action is not entirely characterized but may involve heme; sequences in the 3′ non-coding region of ferritin mRNA can modulate regulation. Ferritin mRNA is the first eukaryotic mRNA for which a conserved regulatory sequence and regulator protein have been identified. The same RNA-protein motif is used, through iron-dependent degradation of transferrin receptor mRNA, to decrease synthesis of the receptor and cellular iron uptake. The regulatory structure of the transferrin receptor mRNA is composed, in part, of five copies of the IRE in the 3′ noncoding region. IRE structure, probed by cleavage with RNases T1, V1, 1,10-phenanthroline-Cu or modification with dimethyl sulfate, is a hairpin loop with conformational variations dependent on magnesium; a basepaired region flanking the IRE is also structurally sensitive to magnesium. Similar results were obtained with a synthetic 55-mer containing the IRE and with a full-length in vitro transcript with a G→A substitution in the loop. However, in both cases, the IRE structure was closer to the computer-predicted structure and was less affected by magnesium than in native ferritin mRNA, indicating the importance of the loop sequence and RNA interactions outside the IRE structure. The combined IRE +flanking regions in six different ferritin mRNAs form a structure very close to the cap where interference with translational initiation is likely.
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References
Berry JO, Carr JP, Klessig DF (1988) mRNAs encoding ribulose-1,5-bisphosphate carboxylase remain bound to polysomes but are not translated in amaranth seedlings transferred to darkness. Proc Natl Aca Sci USA 85:4190–4194
Casey JL, Hentze MW, Koeller DM, Caughman SW, Rouault TA, Klausner RD, Harford JB (1988) Iron-responsive elements: regulatory RNA sequences that control mRNA levels and translation. Science 240:924–928
Constanzo F, Colombo M, Staempfli S, Santoro C, Marone M, Frank R, Delius H, Cortese R (1986) Structure of gene and pseudogenes of human apoferritin H. Nucleic Acids Res 14:721–736
Dickey LF, Sreedharan S, Theil EC, Didsbury JR, Wang YH, Kaufman RE (1987) Difference in the regulation of messenger RNA for housekeeping and specialized-cell ferritin: a comparison of three distinct ferritin complementary DNAs, the corresponding subunits, and identification of the first processed pseudogene in amphibia. J Biol Chem 262:7901–7907
Dickey LF, Wang YH, Shull GE, Wortmann IA III, Theil EC (1988) The importance of the 3′-untranslated region in the translational control of ferritin mRNA. J Biol Chem 263:3071–3074
Freier SM, Kierzek R, Jaeger JA, Sugimoto N, Caruthers MH, Neilson T, Turner DH (1986) Improved free-energy parameters for predictions of RNA duplex stability. Proc Natl Acad Sci USA 83:9373–9377
Gossen B, Caughman SW, Harford JB, Klausner RD, Hentze MW (1991) Translational repression by a complex between the iron-responsive element of ferritin mRNA and its specific cytoplasmic binding protein is position dependent in vivo. EMBO J, in the press
Koeller DM, Casey JL, Hentze MW, Gerhardt EM, Chan LN, Klausner RD, Harford JB (1989) A cytosolic protein binds to structural elements within the iron regulatory region of the transferrin receptor mRNA. Proc Natl Acad Sci USA 85:787–1791
Leibold EA, Munro HN (1987) Characterization and evolution of the expressed rat ferritin light subunit gene and its pseudogene family. J Biol Chem 262:7335–7341
Leibold EA, Munro HN (1988) 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 USA 85:2172–2175
Lin JJ, Daniels-McQueen S, Patino MM, Gaffield L, Walden WE, Thach RE (1990) Derepression of ferritin messenger RNA translation by human in vitro. Science 247:74–77
Lindquist S (1987) The heat shock response. Annu Rev Biochem 55:1151–1191
Milligan TF, Groebe DR, Witherall GW, Uhlenbeck OC (1987) Oligoribonucleotide synthesis using T1 polymerase and synthetic DNA templates. Nucleic Acids Res 15:8787–8798
Moskaitis JE, Pastori RL, Schoenberg DR (1990) Sequence ofXenopus laevis ferritin mRNA. Nucleic Acids Res 18:2184
Mullner EW, Neupert B, Kuhn LC (1989) A specific mRNA binding factor regulates the iron-dependent stability of cytoplasmic transferrin receptor mRNA. Cell 58:373–382
Murray MT, White K, Munro HN (1987) Conservation of ferritin heavy subunit gene structure: implications for the regulation of ferritin gene expression. Proc Natl Acad Sci USA 84:7438–7442
Owen D, Kuhn LC (1987) Noncoding 3′ sequences of the transferrin receptor gene are required for mRNA regulation by iron. EMBO J 6:1287–1293
Rouault TA, Hentze MW, Haile DJ, Harford JB, Klausner RD (1989) The iron-responsive element binding protein: a method for the affinity purification of a regulatory RNA-binding protein. Proc Natl Acad Sci USA 86:5768–5772
Santoro C, Marone M, Ferrone M, Costanzo F, Colombo M, Minganti C, Cortese R, Silengo L (1986) Cloning of the gene coding for human L apoferritin. Nucleic Acids Res 14:2863–2876
Schaefer FV, Theil EC (1981) The effect of iron on the synthesis and amount of ferritin in red blood cells during ontogeny. J Biol Chem 256:1711–1715
Shaw G, Kamen R (1986) A conserved AU sequence from the 3′ untranslated region of GM-CSF mRNA mediates selective mRNA degradation. Cell 46:659–667
Shull GE, Theil EC (1982) Translational control of ferritin synthesis by iron in embryonic reticulocytes of the bullfrog. J Biol Chem 257:14187–14191
Sigman DS, Chen CB (1990) Chemical nucleases: new reagents in molecular biology. Annu Rev Biochem 59:207–236
Standart NM, Bray SJ, George EL, Hunt T, Ruderman JV (1985) The small subunit of ribonucleotide reductase is encoded by one of the most abundant translationally regulated maternal RNAs in clam and sea urchin eggs. J Cell Biol 100:1968–1976
Stevens PW, Dodgson JB, Engel JD (1987) Structure and expression fo the chicken ferritin H-subunit gene. Mol Cell Biol 7:1751–1758
Swenson KF, Borge N, Pietrini G, Ruderman JV (1987) Three translationally regulated mRNAs stored in cytoplasm of clam oocytes. Dev Biol 123:10–16
Theil EC (1990) Regulation of ferritin and transferrin receptor mRNAs. J Biol Chem 265:4771–4774
Walden WE, Patino MM, Gaflield L (1989) Purification of a specific repressor of ferritin mRNA translation from rabbit liver. J Biol Chem 264:13765–13769
Wang YH, Sczekan SR, Theil EC (1990) Structure of the 5′ untranslated region of ferritin mRNA in solution. Nucleic Acids Res 18:4463–4468
White K, Munro FIN (1988) Induction of ferritin subunit synthesis by iron is regulated at both the transcriptional and translational levels. J Biol Chem 263:8938–8942
Zahringer J, Baliga BS, Munro HN (1976) Novel mechanism for translational control in regulation of ferritin synthesis by iron. Proc Natl Acad Sci USA 73:857–861
Zucker M, Steigler P (1981) Optimal computer folding of large RNA sequences using thermodynamics and auxiliary information. Nucleic Acids Res 9:133–148
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Wang, YH., Lin, PN., Sczekan, S.R. et al. Ferritin mRNA probed, near the iron regulatory region, with protein and chemical (1,10-phenanthroline-Cu) nucleases A possible role for base-paired flanking regions. Biol Metals 4, 56–61 (1991). https://doi.org/10.1007/BF01135558
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DOI: https://doi.org/10.1007/BF01135558