title: Selection of RNA oligonucleotides that can modulate human dicer activity in vitro.
abstract: Human ribonuclease Dicer is an enzyme that excises small regulatory RNAs from perfectly or partially double-stranded RNA precursors. Although Dicer substrates and products have already been quite well characterized, our knowledge about cellular factors regulating the activity of this enzyme is still limited. To learn more about this problem, we attempted to determine whether RNA could function not only as a Dicer substrate but also as its regulator. To this end, we applied an in vitro selection method. We identified 120 RNA oligomers binding human Dicer. Sixteen of them were subjected to more detailed in vitro studies. We found that 6 out of 16 oligomers affected Dicer ability to digest pre-microRNAs (miRNAs), although most of them were cleaved by this enzyme. For the 6 most active oligomers the putative mechanism of Dicer inhibition was determined. Three oligomers were classified as typical competitive inhibitors and one as an allosteric inhibitor. The remaining 2 oligomers acted as selective inhibitors. They affected the production of 1 miRNA, whereas the formation of other miRNAs was hardly influenced. In general, the data obtained suggest that one can modulate the generation of specific miRNAs by using RNA oligomers. Moreover, we found that sequences similar to those of the selected oligomers can be found within the molecules composing human transcriptome.
authors: Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland.
authors: Agata
authors: A
authors: Tyczewska
authors: Anna
authors: A
authors: Kurzyńska-Kokorniak
authors: Natalia
authors: N
authors: Koralewska
authors: Aleksandra
authors: A
authors: Szopa
authors: Anna M
authors: AM
authors: Kietrys
authors: Jan
authors: J
authors: Wrzesiński
authors: Tomasz
authors: T
authors: Twardowski
authors: Marek
authors: M
authors: Figlerowicz
mesh_terms: D000494:Allosteric Regulation; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000494:pharmacology; D001483:Base Sequence; D001667:Binding, Competitive; D003198:Computer Simulation; D053487:DEAD-box RNA Helicases / Q000037:antagonists & inhibitors*; D057075:Enzyme Assays; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D035683:MicroRNAs / Q000235:genetics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D043244:Ribonuclease III / Q000037:antagonists & inhibitors*; D052156:SELEX Aptamer Technique; D059467:Transcriptome
chemical_list: D052157:Aptamers, Nucleotide; D035683:MicroRNAs; C408087:DICER1 protein, human; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases