Design principles of transcription factors with intrinsically disordered regions

TL;DR

This paper uncovers how intrinsically disordered regions (IDRs) in transcription factors improve their ability to find and bind to DNA targets quickly, revealing key design principles that enhance gene regulation efficiency.

Contribution

It identifies the fundamental design principles of IDRs in transcription factors that optimize binding affinity and search time, supported by a model aligned with experimental data.

Findings

IDRs significantly improve TF binding affinity.

IDRs reduce the search time for DNA targets.

Model predictions align with experimental observations.

Abstract

Transcription Factors (TFs) are proteins crucial for regulating gene expression. Effective regulation requires the TFs to rapidly bind to their correct target, enabling the cell to respond efficiently to stimuli such as nutrient availability or the presence of toxins. However, the search process is hindered by slow diffusive movement and the presence of `false' targets --DNA segments that are similar to the true target. In eukaryotic cells, most TFs contain an Intrinsically Disordered Region (IDR), which is commonly assumed to behave as a long, flexible polymeric tail composed of hundreds of amino acids. Recent experimental findings indicate that the IDR of certain TFs plays a pivotal role in the search process. However, the principles underlying the IDR's role remain unclear. Here, we reveal key design principles of the IDR related to TF binding affinity and search time. Our results demonstrate that the IDR significantly enhances both of these aspects. Furthermore, our model shows good agreement with experimental results, and we propose further experiments to validate the model's predictions.