R35GM139564

Mechanisms of Chromatin Regulation of Transcription - Project Summary

Over the past decade, the Poirier Lab has worked to contribute to the fields of chromatin biology and transcription regulation by developing a research program that is focused on the mechanisms by which chromatin and nucleosome structural dynamics regulate genome accessibility to transcription regulatory complexes.

We have developed and applied, on our own and through collaborations, a wide range of experimental tools that enable mechanistic studies. These tools include single molecule fluorescence, single molecule force spectroscopy, ensemble fluorescence, and histone chemical ligations. By combining these techniques, we have quantitatively investigated how chromatin regulators, including histone post-translational modifications (PTMs), PTM binding proteins (readers), chromatin remodelers, linker histones, and transcription factors, function to control genome accessibility to chromatin regulatory complexes.

Building off this work, we propose to investigate two central questions in the fields of chromatin biology and transcription in the coming five years:

(I) How do pioneer transcription factors target their recognition sites within compact nucleosomes and chromatin, and then facilitate chromatin decompaction?
(II) How do epigenetic regulators function together to synergistically or antagonistically regulate genome accessibility to transcription regulatory complexes?

Pioneer factors (PFs) are master regulators of cell differentiation and are correlated with nucleosome depletion. They somehow access their binding sites within compact chromatin that are inaccessible to canonical transcription factors (TFs). Furthermore, PF dysfunction is strongly correlated with diseases, most notably cancer. By combining single molecule and ensemble studies, we will directly test distinct mechanisms of PF function and determine what differentiates PFs from canonical TFs. Furthermore, through collaborative work, we will investigate the same PFs in vivo to determine how the PF mechanisms that emerge from our in vitro studies impact their functions in vivo. This first direction will provide key insights into how pioneer factors gain access to their sites within compact chromatin and what differentiates PFs from canonical TFs.

Epigenetic regulators, including histone PTMs and their readers and writers, are critical to organismal development, aging, and numerous diseases, including cancer. We and others have investigated these regulators individually, yet how they function in combination remains largely unknown. Leveraging our ability to prepare core histones and, most recently, linker histones with any combination of PTMs, histone H3 readers, and biochemical quantities of endogenous human SAGA and ATAC complexes, we will use single molecule, ensemble, and ES cell-based methods to determine how biologically relevant combinations of these regulators control accessibility to canonical TFs and influence PFs. This second direction will provide a mechanistic and functional foundation for understanding how key epigenetic transcriptional regulators differentially control chromatin dynamics, accessibility, and transcription.

Ohio State University

THE NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES (NIGMS) SUPPORTS BASIC RESEARCH THAT INCREASES OUR UNDERSTANDING OF BIOLOGICAL PROCESSES AND LAYS THE FOUNDATION FOR ADVANCES IN DISEASE DIAGNOSIS, TREATMENT, AND PREVENTION. NIGMS ALSO SUPPORTS RESEARCH IN SPECIFIC CLINICAL AREAS THAT AFFECT MULTIPLE ORGAN SYSTEMS: ANESTHESIOLOGY AND PERI-OPERATIVE PAIN, CLINICAL PHARMACOLOGY ?COMMON TO MULTIPLE DRUGS AND TREATMENTS, AND INJURY, CRITICAL ILLNESS, SEPSIS, AND WOUND HEALING.? NIGMS-FUNDED SCIENTISTS INVESTIGATE HOW LIVING SYSTEMS WORK AT A RANGE OF LEVELSFROM MOLECULES AND CELLS TO TISSUES AND ORGANSIN RESEARCH ORGANISMS, HUMANS, AND POPULATIONS. ADDITIONALLY, TO ENSURE THE VITALITY AND CONTINUED PRODUCTIVITY OF THE RESEARCH ENTERPRISE, NIGMS PROVIDES LEADERSHIP IN SUPPORTING THE TRAINING OF THE NEXT GENERATION OF SCIENTISTS, ENHANCING THE DIVERSITY OF THE SCIENTIFIC WORKFORCE, AND DEVELOPING RESEARCH CAPACITY THROUGHOUT THE COUNTRY.

93.859 - Biomedical Research and Research Training

National Institute of General Medical Sciences (NIGMS) [HHS - NIH]

HHS Office of the Assistant Secretary for Financial Resources (ASFR) [HHS]

Columbus, Ohio 432101117 United States

Single Zip Code

Maximizing Investigators' Research Award (R35 - Clinical Trial Optional) (PAR-19-367)

Amendment Since initial award the total obligations have increased 516% from $579,025 to $3,568,421.