Uncovering the DNA binding properties of the GATA4 and TBX5 transcription factor complex

Abstract

Transcription factors (TFs) are essential master regulators of gene expression. These DNA binding proteins are fundamental for cellular differentiation during development. Eukaryotic TFs are notorious for not working alone and they often bind DNA as multimeric protein complexes to regulate gene expression. GATA4 and TBX5 are transcription factors that are central components of the gene regulatory network of human heart development and function. Recent studies have determined the binding specificity of these transcription factors as monomers. However, the DNA‐binding properties of the cooperative complex between GATA4 and TBX5 remain undetermined. Based on this, we want to know the intrinsic DNA binding preferences and the emergent properties that result from the cooperative complex formed by GATA4 and TBX5. We used a cell‐free protein expression system to produce GATA4 and TBX5, and we validated their monomeric and complex DNA‐binding activity through an Electrophoretic Mobility Shift Assay (EMSA). Subsequently, we successfully determined the in vitro DNA‐binding specificity of the GATA4:TBX5 complex using Systematic Evolution of Ligands by Exponential Enrichment (SELEX‐seq). For further studies, we will use this data to computationally predict genome‐wide recognition sites of this transcription factor complex. The findings of this study will help understand the DNA‐recognition rules of the GATA4:TBX5 complex and its potential roles in normal heart development.Support or Funding InformationThis research was supported by:NIH SC1GM127231NSF PR‐LSAMP #1400868