Single-molecule tracking reveals two low-mobility states for transcriptional regulators in the nucleus

KAUSTUBH WAGH; STAVREVA, DIANA A.; RIKKE A.M. JENSEN; VILLE PAAKINAHO; GREGORY FETTWEIS; R. LOUIS SCHILTZ; DANIEL WUSTNER; SUSANNE MANDRUP; THOMAS A JOHNSON; MANAN KRISHNAMURTHY; DIEGO M PRESMAN; UPADHYAYA, ARPITA; GORDON L. HAGER

Floriana

Congreso; A 20/20 vision of the future of nuclear receptors; 2022

EMBO

How transcription factors (TFs) navigate the complex nuclear environment to bindspecific loci and assemble the transcriptional machinery remains elusive. Usingsingle-molecule tracking and machine learning, we show that a structural chromatincomponent (histone 2B), many different TFs and their coregulators display twocommon low-mobility states. These low-mobility states exhibit distinct explorationareas (~130-180nm2 versus 250-350nm2) over time periods of seconds to minutes.The proportion of these two low-mobility states, as well as the percentage of unboundmolecules, varies with different TFs and can be modulated in live cells. For example,ligand activation of steroid hormone receptors (GR, AR, PR, ER) results in a dramaticincrease in the lowest mobility state. Mutational analysis of nuclear receptors revealsthat only the lowest mobility state requires an intact DNA-binding domain. Also, a GRmutant that is constitutively tetrameric has an increased percentage of the lowestmobility state compared to wild type. The mobility states are not spatially separated,as previously believed, but a single molecule can switch back and forth between states.Together, our results identify two common and distinct low-mobility states of histone2Band TFs that may correlate with transcriptional regulation in mammalian cells