Study of the i-motif stability during the cell cycle progression by in‑cell NMR spectroscopy

Viskova Pavlina 1, ⃰, Maturova Eva 1, Krafcikova Michaela 1,2, Dzatko Simon 1, Loja Tomas 1, Rynes Jan 1, Mergny Jean-Louis 2,3,4, Foldynova-Trantirkova Silvie 1,2, Trantirek Lukas 1,2

1 Central European Institute of Technology, Masaryk University, Brno, Czech Republic

2 Institute of Biophysics of the AS CR, v.v.i., Brno, Czech Republic

3CNRS UMR9187, INSERM U1196, Université Paris Sud, Université Paris Saclay, Orsay 91405, France

4CNRS UMR9187, INSERM U1196, Insitut Curie, PSL Research University, Orsay 91405, France

*email: pavlina.viskova@ceitec.muni.cz

 

I-motifs are non-canonical four-stranded DNA structures formed within cytosine (C)-rich DNA [1]. Under in vitro conditions, the formation of these structures strongly depends on pH and ionic strength [2, 3]. While the i-motifs readily form under in vitro conditions of acidic pH and low ionic strength, their formation propensity at close to physiological conditions is compromised. Yet, the i-motifs exist in vivo [5]. Recently, their active role in the regulation of gene expression and telomeric maintenance has been proposed [6].

Cell cycle progression is accompanied by changes in both intracellular pH and ionic strength [4]. As recently demonstrated by Zeraati et al., the in vivo occurrence of the i-motifs changes during the cell cycle [7]. Whether the i-motif formation and the i-motif regulated gene expression is coupled with reorganization of the chromatin or whether it is a consequence of the fluctuations in the environmental parameters of the cell, such as pH or ionic strength, remains unclear.

Here, we report on investigations of formation of the i-motifs in separate phases of the cell cycle using non-invasive in-cell NMR spectroscopy.

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Acknowledgement: This research was supported by the grant from Czech Science Foundation (19-26041X), by the grant from Ministry of Health of the Czech Republic (NV19-08-00450), and by the project SYMBIT (CZ.02.1.01/0.0/0.0/15_003/0000477) funded by the European Regional Development Fund and Ministry of Education, Youth, and Sports (MEYS) of the Czech Republic. MEYS is also acknowledged for its support of access to research infrastructure (CEITEC 2020 LQ1601; CIISB-LM2018127; Czech-BioImaging LM2018129; EATRIS-CZ LM2018133).