Within the eukaryotic cell nucleus, DNA is associated with core histones to form nucleosomes; which are further assembled with ancillary proteins into a multi-faceted complex known as chromatin. This complex brings about the orderly packaging of the immense length of DNA within the tiny volume of the nucleus. In addition, elements of the chromatin complex are directly involved in the regulation of multiple processes within the nucleus that involve DNA. Indeed, a large portion of signal transduction within the cell nucleus appears to ultimately direct the post-translational modification of the core histone proteins and, in several cases, mutations in enzymes that carry out these modifications have been linked to various diseases including cancers in humans. In the last 3-5 years, much effort has been devoted to the elucidation and biochemical purification of the regulatory machinery and enzymes that mediate core histone posttranslational modifications. Interestingly, nearly all of these modifications occur within specialized regions known as the core histone tail domains. Biophysical experiments have shown that the tail domains are key components in regulating the structure and function of chromatin at multiple levels. Moreover, posttranslational modifications in these domains are thought to modulate this histone tail-directed regulation. However, the mechanism by which they define chromatin structures - and ultimately the functionality of the underlying DNA - remains unknown. The primary goal of the work described in this proposal is to elucidate the molecular details and the mechanisms by which the core histone tail domains dictate the structural and functional state of the chromatin fiber. The fiber is formed by the folding up of strings of nucleosomes and is a key structure regulated by the tail domains. However little is known regarding molecular interactions of the tail domains. Recently have shown that the tails make precise and localized interactions within nucleosomes. Using a novel site-directed chemical mapping approach, we will examine histone tail interactions in a variety of model chromatin complexes. We will focus on potential inter-nucleosomal interactions likely to be specifically involved in stabilizing the condensed chromatin fiber. Further, we will use a chemical protection approach and NMR of specifically labeled core histones to study the salt-dependent binding stability of individual histone tails within nucleosomes. In addition, we will use these same methods to examine the effects of specific patterns of histone acetylation and a chromatin remodeling activity on histone-DNA interactions.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM052426-13
Application #
7228849
Study Section
Cell Development and Function Integrated Review Group (CDF)
Program Officer
Preusch, Peter C
Project Start
1995-05-01
Project End
2008-04-30
Budget Start
2007-05-01
Budget End
2008-04-30
Support Year
13
Fiscal Year
2007
Total Cost
$267,615
Indirect Cost
Name
University of Rochester
Department
Biochemistry
Type
Schools of Dentistry
DUNS #
041294109
City
Rochester
State
NY
Country
United States
Zip Code
14627
Mishra, Laxmi Narayan; Hayes, Jeffrey J (2018) A nucleosome-free region locally abrogates histone H1-dependent restriction of linker DNA accessibility in chromatin. J Biol Chem 293:19191-19200
Tucker, Christopher; Bhattacharya, Soumyaroop; Wakabayashi, Hironao et al. (2018) Transcriptional Regulation on Aneuploid Chromosomes in Divers Candida albicans Mutants. Sci Rep 8:1630
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Wakabayashi, Hironao; Tucker, Christopher; Bethlendy, Gabor et al. (2017) NuA4 histone acetyltransferase activity is required for H4 acetylation on a dosage-compensated monosomic chromosome that confers resistance to fungal toxins. Epigenetics Chromatin 10:49
Cutter, Amber R; Hayes, Jeffrey J (2017) Linker histones: novel insights into structure-specific recognition of the nucleosome. Biochem Cell Biol 95:171-178
Tencer, Adam H; Cox, Khan L; Di, Luo et al. (2017) Covalent Modifications of Histone H3K9 Promote Binding of CHD3. Cell Rep 21:455-466
Murphy, Kevin J; Cutter, Amber R; Fang, He et al. (2017) HMGN1 and 2 remodel core and linker histone tail domains within chromatin. Nucleic Acids Res 45:9917-9930
Bednar, Jan; Garcia-Saez, Isabel; Boopathi, Ramachandran et al. (2017) Structure and Dynamics of a 197 bp Nucleosome in Complex with Linker Histone H1. Mol Cell 66:384-397.e8
Gatchalian, Jovylyn; Wang, Xiaodong; Ikebe, Jinzen et al. (2017) Accessibility of the histone H3 tail in the nucleosome for binding of paired readers. Nat Commun 8:1489
Black, Paul J; Miller, Adam S; Hayes, Jeffrey J (2016) Radioresistance of GGG sequences to prompt strand break formation from direct-type radiation damage. Radiat Environ Biophys 55:411-422

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