DROSOPHILA FERRITIN MESSENGER-RNA - ALTERNATIVE RNA SPLICING REGULATES THE PRESENCE OF THE IRON-RESPONSIVE ELEMENT

Several mRNAs encoding the same ferritin subunit of Drosophila melanog aster were identified. Alternative RNA splicing and utilisation of dif ferent polyadenylation sites were found to generate the transcripts. T he alternative RNA splicing results in ferritin transcripts with four unique 5' untranslated regions. Only one of them contains an iron-resp onsive element. The iron-responsive element was found to bind in vitro specifically to human recombinant iron regulatory protein 1, Furtherm ore, the ferritin subunit mRNAs are differentially expressed during de velopment, Our data provides the first molecular evidence that the pre sence of iron-responsive element in a ferritin mRNA is regulated by al ternative RNA splicing. (C) 1998 Federation of European Biochemical So cieties.