I-Motif, not G-quadruplex, stability regulates insulin expression.

ABSTRACT: The insulin-linked polymorphic region (ILPR) is a variable number tandem repeat located in the promoter of the human insulin gene. This G-rich sequence can fold into four-stranded G-quadruplex DNA structures, while its complementary C-rich strand forms i-motifs. The ILPR varies in repeat number and sequence composition, but the relationship between sequence diversity, DNA structure, and insulin gene regulation remains poorly understood. Although both G-quadruplexes and i-motifs have been implicated in transcriptional control, their relative contributions, particularly when formed on complementary strands of the same locus, are unclear. Here, we characterized the structure and stability of nine ILPR-based sequences using biophysical techniques and luciferase reporter assays. We demonstrate

SUBMITTER: Guneri D 

PROVIDER: S-EPMC12852952 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature