Schematic illustration showing that only DynaTag captures TF interactions by using physiological salt concentrations (110鈥塵M KCl, 10鈥塵M NaCl, 1鈥塵M MgCl2) during nuclei wash steps. In contrast, the use of 150鈥塵M NaCl or 300鈥塵M NaCl or KCl lead to untargeted tagmentation or allows only for the targeting of histone marks, respectively. Credit: Nature Communications (2025). DOI: 10.1038/s41467-025-61797-9
The binding of proteins to DNA is crucial for producing other proteins, ensuring that all the necessary processes in cells are performed, and for switching genes on or off. Proteins that bind to DNA are called transcription factors. Due to the dynamic interactions of transcription factors with DNA, it is difficult to determine where in the genome transcription factor鈥揇NA interactions occur.
A research team at the University of Cologne has now developed the DynaTag method, which reliably identifies these interactions. If the cell nuclei are intact, DynaTag has proven effective with low-input samples and even at the level of the individual cell. The study, "DynaTag for efficient mapping of transcription factors in low-input samples and at single-cell resolution," is in Nature Communications.
"DynaTag outperforms existing methods such as ChIP-seq and CUT&RUN in terms of sensitivity and resolution of results. The new method delivers high-resolution mapping of the DNA regions where transcription factors bind," says Dr. Robert H盲nsel-Hertsch, Principal Investigator at the Center for Molecular Medicine Cologne (CMMC) and leader of the study.
In complex organisms such as animals with different tissues and cell types, it is difficult to identify where transcription factors bind to DNA in the genome. According to the researchers, this new method, which enables the analysis of single cells across various tissues, could therefore significantly enhance our understanding of developmental biological processes and disease mechanisms in physiologically relevant systems.
In addition, the method can identify the activity of transcription factors in tissue samples. This is significant for clinical research, as tissue samples are routinely obtained from patients for pathological examination.
The researchers demonstrated the method's advantages in a study on small cell lung cancer in a mouse model. The research group led by H盲nsel-Hertsch examined the binding of transcription factors in small cell lung tumors before and after the administration of chemotherapy.
"It had already been established that certain signaling pathways promoting resistance or metastasis are activated after chemotherapy in small cell lung cancer. However, it was not known which transcription factors regulate these signaling pathways," says H盲nsel-Hertsch.
"With the help of DynaTag, we were able to identify specific transcription factors that show increased binding to genes belonging to these signaling pathways after chemotherapy and are likely to promote further tumor growth."
DynaTag thus addresses a fundamental technical limitation and opens up new avenues for studying epigenetic regulation in health and disease鈥攑articularly in samples that are difficult to access or in rare cell populations.
More information: Pascal Hunold et al, DynaTag for efficient mapping of transcription factors in low-input samples and at single-cell resolution, Nature Communications (2025).
Journal information: Nature Communications
Provided by University of Cologne