진학프로석·박사 채용 접수 플랫폼

KEY WORDS: nucleic acid binding proteins, protein-nucleic acid interactions, Dicer ribonuclease,
G-quadruplexes, regulatory RNAs, regulation of gene expression

Principal Investigator: Assoc. Prof. Anna Kurzynska-Kokorniak, PhD, DSc

Research topic: functional implications of interactions between the ribonuclease Dicer and DNA/RNA molecules adopting the G-quadruplex structures

I. Project description

Accumulating evidence indicates that DNA/RNA G-quadruplexes (helical structures containing guanine tetrads) serve important regulatory roles in fundamental biological processes such as DNA replication, transcription and translation, while aberrant G-quadruplex formation is linked to genome instability and cancer. Understanding the biological functions played by G-quadruplexes requires detailed knowledge of their protein interactome. Our newest finding indicates that ribonuclease Dicer – the enzyme known for its important role in the miRNA/siRNA biogenesis pathways, apart from its canonical substrates (pre-microRNAs and double-stranded RNAs), may also bind G-quadruplex structures present within RNA and DNA molecules (doi: 10.1007/s00018-021-03795-w). Planned research focuses mainly on the human Dicer (hDicer). During the project implementation, we would like to answer the following questions:

- What are the potential functional implications of interactions between hDicer and RNA molecules adopting the G-quadruplex structures?

- Whether nuclear hDicer can bind to the telomeric G-quadruplexes, and other G-quadruplex structures formed within chromatin? If yes, what are the potential biological implications of these interactions?

Using the developed cell models, immunoprecipitation techniques and next-generation sequencing (NGS), we plan to identify and then characterize the pool of cellular DNAs and RNAs adopting G-quadruplex structures bound by hDicer. To confirm the interactions between hDicer and G-quadruplexes in the cell, we will use advanced imaging techniques, including confocal microscopy. Moreover, imaging co-localization experiments will be performed with the MINFLUX nanoscope, a new technology which enables not only the identification of the interaction and the distance between the two targets, but also allows for unambiguous verification whether the two targets are next to each other, and hence whether they indeed interact. Based on all the collected data, the potential functional implications of Dicer’s interactions with the DNA and RNA molecules adopting G-quadruplex structures will be inferred.

Research shall be carried out within the project 2021/41/B/NZ2/03781, entitled “Close Encounters of the Third Kind: what happens when ribonuclease Dicer encounters in the cell RNA and DNA adopting G-quadruplex structures”, funded by the National Science Centre.

IBCH PAS is one of the leading scientific units in Poland and conducts research activities in the field of chemistry, molecular biology and biomedicine. The Institute provides access to technologically advanced research equipment.