Dissociation rate compensation mechanism for budding yeast pioneer transcription factors
- Ohio State University, United States
- The Pennsylvania State University, United States
Abstract
Nucleosomes restrict the occupancy of most transcription factors (TF) by reducing binding and accelerating dissociation, while a small group of TFs have high affinities to nucleosome-embedded sites and facilitate nucleosome displacement. To mechanistically understand this process, we investigated two S. cerevisiae TFs, Reb1 and Cbf1. We show these factors bind their sites within nucleosomes with similar affinities to naked DNA, trapping a partially unwrapped nucleosome without histone eviction. Both the binding and dissociation rates of Reb1 and Cbf1 are significantly slower at the nucleosomal sites relative to DNA, demonstrating that the high affinities are achieved by increasing the dwell time on nucleosomes to compensate for reduced binding. Reb1 also shows slow migration rate in the yeast nuclei. These properties are similar to human pioneer factors (PFs), suggesting the mechanism of nucleosome targeting is conserved from yeast to human.
Data availability
All analyzed data generated is included in the manuscript. In supplementary file 1, we include 6 supplementary tables. Table S1 documents all binding affinity measurements from this study. Table S2 documents measured binding rates from single molecule experiments. Table S3 documents relative binding affinities (Nuc/DNA) for ensemble and single molecule experiments. Table S4 documents the primers for in vitro experiments. Table S5 documents quality control information from single molecule experiments. Table S6 documents the primers used for FRAP experiments. Videos supporting this study have been deposited to Zenodo and are available under the doi:10.5281/zenodo.2595208
-
Dissociation rate compensation mechanism for budding yeast pioneer transcription factorsZenodo, doi:10.5281/zenodo.2595208.
Article and author information
Author details
Funding
National Institutes of Health (R01 GM121858)
- Lu Bai
- Michael G Poirier
National Institutes of Health (R01 GM121966)
- Michael G Poirier
National Institutes of Health (T32 GM086252)
- Benjamin T Donovan
National Science Foundation (1516979)
- Michael G Poirier
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2019, Donovan et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 3,958
- views
-
- 574
- downloads
-
- 83
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Dissociation rate compensation mechanism for budding yeast pioneer transcription factors
eLife 8:e43008.
https://doi.org/10.7554/eLife.43008
Further reading
-
- Chromosomes and Gene Expression
Chromatin immunoprecipitation (ChIP-seq) is the most common approach to observe global binding of proteins to DNA in vivo. The occupancy of transcription factors (TFs) from ChIP-seq agrees well with an alternative method, chromatin endogenous cleavage (ChEC-seq2). However, ChIP-seq and ChEC-seq2 reveal strikingly different patterns of enrichment of yeast RNA polymerase II (RNAPII). We hypothesized that this reflects distinct populations of RNAPII, some of which are captured by ChIP-seq and some of which are captured by ChEC-seq2. RNAPII association with enhancers and promoters - predicted from biochemical studies - is detected well by ChEC-seq2 but not by ChIP-seq. Enhancer/promoter-bound RNAPII correlates with transcription levels and matches predicted occupancy based on published rates of enhancer recruitment, preinitiation assembly, initiation, elongation, and termination. The occupancy from ChEC-seq2 allowed us to develop a stochastic model for global kinetics of RNAPII transcription which captured both the ChEC-seq2 data and changes upon chemical-genetic perturbations to transcription. Finally, RNAPII ChEC-seq2 and kinetic modeling suggests that a mutation in the Gcn4 transcription factor that blocks interaction with the NPC destabilizes promoter-associated RNAPII without altering its recruitment to the enhancer.
-
- Chromosomes and Gene Expression
- Microbiology and Infectious Disease
Candida glabrata can thrive inside macrophages and tolerate high levels of azole antifungals. These innate abilities render infections by this human pathogen a clinical challenge. How C. glabrata reacts inside macrophages and what is the molecular basis of its drug tolerance are not well understood. Here, we mapped genome-wide RNA polymerase II (RNAPII) occupancy in C. glabrata to delineate its transcriptional responses during macrophage infection in high temporal resolution. RNAPII profiles revealed dynamic C. glabrata responses to macrophages with genes of specialized pathways activated chronologically at different times of infection. We identified an uncharacterized transcription factor (CgXbp1) important for the chronological macrophage response, survival in macrophages, and virulence. Genome-wide mapping of CgXbp1 direct targets further revealed its multi-faceted functions, regulating not only virulence-related genes but also genes associated with drug resistance. Finally, we showed that CgXbp1 indeed also affects fluconazole resistance. Overall, this work presents a powerful approach for examining host-pathogen interaction and uncovers a novel transcription factor important for C. glabrata’s survival in macrophages and drug tolerance.
