Transcription factor dynamics at the single-molecule level

DIEGO M. PRESMAN

CABA

Taller; Chromatin and gene regulation: from gene to genome folding; 2018

IBYME

Population-based assays such as chromatin immunoprecipitation have been employed extensively to investigate the interactions of transcription factors (TFs) with chromatin and are often interpreted in terms of static and sequential binding. However, fluorescence microscopy techniques reveal a more dynamic binding behavior of TFs in live cells. Progressive, technological achievements in the quantitative fluorescence microscopy field are allowing researches from many different areas to start unraveling the dynamic intricacies of biological processes inside living cells. From super-resolution microscopy techniques to tracking of individual proteins, fluorescence microscopy is changing our perspective on how the cell works. While a growing number of research groups are exploring single-molecule studies in living cells, no clear consensus exists on several key aspects of the technique such as image acquisition conditions, photobleaching correction, or analysis of the obtained data. Here, I will describe one way to perform single-molecule tracking (SMT) of transcription factors in living cells. I will present the strengths and limitations of the technique and show examples of different transcription factors. Finally, I will discuss a new biological interpretation of transcriptional regulation that emerges from a novel interpretation of the data