title: TERRA mimicking ssRNAs prevail over the DNA substrate for telomerase in vitro due to interactions with the alternative binding site.
abstract: Telomerase is a key component of the telomere length maintenance system in the majority of eukaryotes. Telomerase displays maximal activity in stem and cancer cells with high proliferative potential. In humans, telomerase activity is regulated by various mechanisms, including the interaction with telomere ssDNA overhangs that contain a repetitive G-rich sequence, and with noncoding RNA, Telomeric repeat-containing RNA (TERRA), that contains the same sequence. So these nucleic acids can compete for telomerase RNA templates in the cell. In this study, we have investigated the ability of different model substrates mimicking telomere DNA overhangs and TERRA RNA to compete for telomerase in vitro through a previously developed telomerase inhibitor assay. We have shown in this study that RNA oligonucleotides are better competitors for telomerase that DNA ones as RNA also use an alternative binding site on telomerase, and the presence of 2'-OH groups is significant in these interactions. In contrast to DNA, the possibility of forming intramolecular G-quadruplex structures has a minor effect for RNA binding to telomerase. Taking together our data, we propose that TERRA RNA binds better to telomerase compared with its native substrate - the 3'-end of telomere DNA overhang. As a result, some specific factor may exist that participates in switching telomerase from TERRA to the 3'-end of DNA for telomere elongation at the distinct period of a cell cycle in vivo. Copyright © 2015 John Wiley & Sons, Ltd.
authors.affiliation: Department of Chemistry and A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.|Skolkovo Institute of Science and Technology, 4 Alfred Nobel Street, Skolkovo, 143025, Russia.
authors.forename: Dulat
authors.initials: D
authors.lastname: Azhibek
authors.affiliation: Department of Chemistry and A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Skvortsov
authors.affiliation: Department of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119992, Russia.
authors.forename: Anna
authors.initials: A
authors.lastname: Andreeva
authors.affiliation: Department of Chemistry and A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.|Skolkovo Institute of Science and Technology, 4 Alfred Nobel Street, Skolkovo, 143025, Russia.
authors.forename: Timofei
authors.initials: T
authors.lastname: Zatsepin
authors.affiliation: Department of Chemistry and A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.
authors.forename: Alexandr
authors.initials: A
authors.lastname: Arutyunyan
authors.affiliation: Department of Chemistry and A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.
authors.forename: Maria
authors.initials: M
authors.lastname: Zvereva
authors.affiliation: Department of Chemistry and A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.
authors.forename: Olga
authors.initials: O
authors.lastname: Dontsova
mesh_terms: D001665:Binding Sites; D002942:Circular Dichroism; D004277:DNA, Single-Stranded / Q000737:chemistry; D054856:G-Quadruplexes; D006801:Humans; D066298:In Vitro Techniques; D009841:Oligonucleotides / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D062085:RNA, Long Noncoding / Q000737:chemistry; D019098:Telomerase / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D004277:DNA, Single-Stranded; D009841:Oligonucleotides; D062085:RNA, Long Noncoding; D019098:Telomerase
keywords: DNA; TERRA RNA; oligonucleotide; telomerase