Post-translational histone modifications are essential to the proper regulation of nearly all DNA-mediated processes, whereas improper modifications lead to numerous disease states. Histone modifications exist in the context of chromatin, a complex assembly of DMA, histones (H2A, H2B, H3, and H4), and chromatin- associated proteins. Chromatin exhibits a complex hierarchy of higher-order structures, and our long-term goal is to elucidate the interplay between higher-order chromatin structure and histone modifications. This proposal details studies that both capitalize on our ability to generate chromatin model systems containing uniformly modified H3 and H4 histones and on our recent discovery that histone H4 lysine 16 acetylation is sufficient to directly disrupt both intra- and intermolecular chromatin compaction. The purpose of this work is to gain an in depth understanding of how H3 and H4 histone tail acetylation, H2B carboxy- terminal triacetylation, and H2B monoubiquitination affect higher-order chromatin structure individually and in combination, as well as how these marks influence subsequent histone modifications.
Three specific aims have been proposed to address these questions. First, we will utilize various chromatin model systems containing varying patterns and levels of histone H3 and H4 acetylation to understand the mechanistic details of how histone tail acetylation affects higher-order chromatin structure. Second, we will elucidate how changes in higher-order chromatin structure direct histone tail acetylation using a combination of biophysical, enzymatic and genetic approaches. Third, we will develop novel techniques for introducing H2B carboxy- terminal modifications to determine their structural and functional roles. Completion of these aims will help to define how post-translational histone modifications and higher-order chromatin structure directly influence one another. By extending our understanding of the role of histone modifications into an area that has not previously been intensively studied, we will obtain a better mechanistic understanding of the normal role of these modifications. Additionally, this understanding can lead to a better appreciation of how improper utilization of these modifications results in diseases, including various cancers and congenital defects, leading to better disease diagnosis and treatment.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM079663-03S1
Application #
7907356
Study Section
Molecular Genetics A Study Section (MGA)
Program Officer
Carter, Anthony D
Project Start
2009-09-01
Project End
2011-08-31
Budget Start
2009-09-01
Budget End
2011-08-31
Support Year
3
Fiscal Year
2009
Total Cost
$450,433
Indirect Cost
Name
Iowa State University
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
005309844
City
Ames
State
IA
Country
United States
Zip Code
50011
Azzaz, Abdelhamid M; Vitalini, Michael W; Thomas, Andrew S et al. (2014) Human heterochromatin protein 1? promotes nucleosome associations that drive chromatin condensation. J Biol Chem 289:6850-61
Lee, Whasil; Strümpfer, Johan; Bennett, Vann et al. (2012) Mutation of conserved histidines alters tertiary structure and nanomechanics of consensus ankyrin repeats. J Biol Chem 287:19115-21
Lee, Whasil; Zeng, Xiancheng; Rotolo, Kristina et al. (2012) Mechanical anisotropy of ankyrin repeats. Biophys J 102:1118-26
Chatterjee, Nilanjana; Sinha, Divya; Lemma-Dechassa, Mekonnen et al. (2011) Histone H3 tail acetylation modulates ATP-dependent remodeling through multiple mechanisms. Nucleic Acids Res 39:8378-91
Wang, Chien-Chung; Tsong, Tian-Yow; Hsu, Yau-Heiu et al. (2011) Inhibitor binding increases the mechanical stability of staphylococcal nuclease. Biophys J 100:1094-9
Blacketer, Melissa J; Feely, Sarah J; Shogren-Knaak, Michael A (2010) Nucleosome interactions and stability in an ordered nucleosome array model system. J Biol Chem 285:34597-607
Murakami, Takeshi; Takano, Ryuji; Takeo, Satoshi et al. (2010) Stable interaction between the human proliferating cell nuclear antigen loader complex Ctf18-replication factor C (RFC) and DNA polymerase {epsilon} is mediated by the cohesion-specific subunits, Ctf18, Dcc1, and Ctf8. J Biol Chem 285:34608-15
Lee, Whasil; Zeng, Xiancheng; Zhou, Huan-Xiang et al. (2010) Full reconstruction of a vectorial protein folding pathway by atomic force microscopy and molecular dynamics simulations. J Biol Chem 285:38167-72
Sinha, Divya; Shogren-Knaak, Michael A (2010) Role of direct interactions between the histone H4 Tail and the H2A core in long range nucleosome contacts. J Biol Chem 285:16572-81
Lin, Liyun; Fu, Qiang; Williams, Berea A R et al. (2009) Recognition imaging of acetylated chromatin using a DNA aptamer. Biophys J 97:1804-7

Showing the most recent 10 out of 12 publications