Single-molecule Analysis of Glucocorticoid Receptor and Cofactor Action in Living Cells

PAAKINAHO, VILLE*; PRESMAN, DIEGO M.*; BALL, DAVID A.; THOMAS A. JOHNSON; R. LOUIS SCHILTZ; PETER LEVITT; DAVIDE MAZZA; TATSUYA MORISAKI; KARPOVA, TATIANA S.; HAGER, GORDON L.

NATURE COMMUNICATIONS

Nature Publishing group

Año: 2017

2041-1723

Population-based assays 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. Here, we analyze the strengths and limitations of in vivo single-molecule tracking and performed a comprehensive analysis on the intranuclear dwell times of four steroid receptors and a number of known cofactors. While the absolute residence times estimates can depend on imaging acquisition parameters due to sampling bias, our results indicate that only a small proportion of factors are specifically bound to chromatin at any given time. Interestingly, the glucocorticoid receptor and its cofactors affect each other?s dwell times in an asymmetric fashion. Overall, our data indicate transient rather than stable TF-cofactors chromatin interactions at response elements at the single-molecule level.