i-motifs: DNA structures with regulatory functions and therapeutic potential

Area of Science:

• Molecular Biology
• Genomics
• Biochemistry

Background:

• Non-B DNA structures, including i-motifs, represent alternatives to the canonical Watson-Crick double helix.
• I-motifs form in cytosine-rich DNA sequences and are stabilized by specific hydrogen bonding between protonated cytosines.
• These structures can adopt various topologies and are found in functionally important genomic regions like gene promoters and telomeres.

Purpose of the Study:

• To review the molecular mechanisms governing the formation and stability of i-motif DNA structures.
• To explore the biological relevance and regulatory roles of i-motifs in gene expression.
• To highlight the therapeutic potential of targeting i-motif structures for disease treatment.

Main Methods:

• Literature review focusing on studies of i-motif formation, stability, and biological interactions.
• Analysis of DNA sequence context, pH conditions, and protein binding associated with i-motif structures.
• Examination of i-motif roles in gene regulation, particularly in oncogene promoters and repetitive DNA elements.

Main Results:

• I-motif formation depends on cytosine protonation and is influenced by DNA sequence and pH.
• I-motif structures exhibit diverse topologies and interact with proteins and ligands.
• Evidence suggests i-motifs play significant roles in regulating gene expression, especially in oncogenes and telomeric regions.

Conclusions:

• I-motif DNA structures are key regulators of genomic function with implications for gene expression.
• Understanding i-motif behavior provides insights into genomic regulation and disease mechanisms.
• Targeting i-motif structures presents a promising therapeutic strategy for cancer and other complex diseases.