Identification and functional characterization of i-motifs in plants

An i-motif (iM) is a typical quadruplex containing putative i-motif forming sequences (PiMFSs) with cytosine-rich DNA sequences. iMs are stabilized by hemiprotonated C:C+ base pairs under acidic conditions. Accumulating evidence shows that iM folding is determined by various factors, including intrinsic DNA sequences, environmental conditions, ligands, and epigenetic modifications. Combinations of these factors affect in vitro and in vivo (physiological) iM formation. High-throughput methodologies of iMab (iM-specific antibody)-based iM-immunoprecipitation (IP)-seq and CUT&TAG have been successfully applied for characterization of i-motifs in rice (Oryza sativa L.) and humans, respectively, thereby boosting functional studies of iMs and advancing understanding of its biological relevance in both humans and plants.