RT Journal Article
SR Electronic
T1 Transcription factor clusters regulate genes in eukaryotic cells
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 125104
DO 10.1101/125104
A1 Adam J. M. Wollman
A1 Sviatlana Shashkova
A1 Erik G. Hedlund
A1 Rosmarie Friemann
A1 Stefan Hohmann
A1 Mark C. Leake
YR 2017
UL http://biorxiv.org/content/early/2017/04/06/125104.abstract
AB Transcription is regulated through binding factors to gene promoters to activate or repress expression, however, the mechanisms by which factors find targets remain unclear. Using single-molecule fluorescence microscopy, we determined in vivo stoichiometry and spatiotemporal dynamics of a GFP tagged repressor, Mig1, from a paradigm signaling pathway of Saccharomyces cerevisiae. We find the repressor operates in clusters, which upon extracellular signal detection, translocate from the cytoplasm, bind to nuclear targets and turnover. Simulations of Mig1 configuration within a 3D yeast genome model combined with a promoter-specific, fluorescent translation reporter confirmed clusters are the functional unit of gene regulation. In vitro and structural analysis on reconstituted Mig1 suggests that clusters are stabilized by depletion forces between intrinsically disordered sequences. We observed similar clusters of a co-regulatory activator from a different pathway, supporting a generalized cluster model for transcription factors that reduces promoter search times through intersegment transfer while stabilizing gene expression.