Probing the folding pathways of four-stranded intercalated cytosine-rich motifs at single base-pair resolution.
Biochimie
; 199: 81-91, 2022 Aug.
Article
in En
| MEDLINE
| ID: mdl-35452743
ABSTRACT
Cytosine-rich DNA can fold into four-stranded intercalated structures called i-motifs (iMs) under acidic conditions through the formation of hemi-protonated CC+ base pairs. However, the folding and stability of iMs rely on many other factors that are not yet fully understood. Here, we combined biochemical and biophysical approaches to determine the factors influencing iM stability under a wide range of experimental conditions. By using high-resolution primer extension assays, circular dichroism, and absorption spectroscopies, we demonstrate that the stabilities of three different biologically relevant iMs are not dependent on molecular crowding agents. Instead, some of the crowding agents affected overall DNA synthesis. We also tested a range of small molecules to determine their effect on iM stabilization at physiological temperature and demonstrated that the G-quadruplex-specific molecule CX-5461 is also a promising candidate for selective iM stabilization. This work provides important insights into the requirements needed for different assays to accurately study iM stabilization, which will serve as important tools for understanding the contribution of iMs in cell regulation and their potential as therapeutic targets.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cytosine
/
G-Quadruplexes
Language:
En
Journal:
Biochimie
Year:
2022
Document type:
Article