Quantitative modulation of a spatial enhancer through the biophysical properties of a transcription factor binding site.

ABSTRACT: Fine-tuning of gene expression by transcription factors (TFs) is essential for normal development, but how TF binding is converted into precise expression levels is poorly understood. We used a Drosophila enhancer responding to the TF Distal-less (Dll) to investigate this relationship. By combining computational structure analysis and quantifying relative TFBS affinity and enhancer activity, we describe how TF concentration is converted into precise expression across the developing Drosophila wing. We show that, although the regulatory function of the enhancer generally follows the classical Hill equation, several additional terms are needed to describe the effects of affinity, orientation, sequence, and wing region on the maximum achievable expression and position of transcr

SUBMITTER: Fallon C 

PROVIDER: S-EPMC12778045 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature