Poster Abstract: Single-cell mapping of regulatory DNA:Protein interactions

Sang-Ho Yoon, Postdoc, Weill Cornell Medicine

Abstract

Gene expression is governed by epigenomic landscapes comprising transcription factor (TF) or chromatin remodeler (CR) binding. These networks are often disrupted in aging and disease, yet profiling DNA:Protein interactions across diverse cell types and states remains challenging. To address this, we developed D&D-seq, a single-cell immuno-tethering DNA:Protein mapping technology. By coupling species-specific antibody-binding nanobodies to a cytosine base editing enzyme, D&D-seq induces cytosine-to-uracil edits at protein-bound genomic regions, enabling multimodal single-cell analyses with high specificity. We profiled binding of six TFs and one CR in bulk, and validated single-cell CTCF and GATA binding. D&D-seq identified CTCF binding sites in primary human peripheral blood mononuclear cells, and combined with single-cell genotyping, revealed altered CTCF binding in IDH2-mutant hematopoietic cells. This approach expands the scope of single-cell multiomics, enabling direct mapping of TF and chromatin remodeler binding, advancing our understanding of gene regulation in health and disease.