Each time a eukaryotic cell divides it must duplicate, not only its genomic DNA, but the underlying chromatin structure, as well. The faithful propagation of chromatin structure is necessary for the packaging and protection of the eukaryotic genome as well as for the maintenance of epigenetically inherited transcriptional programs. The primary goal of our research program is to decipher the mechanisms by which the primary protein components of chromatin (the core histones H2A, H2B H3 and H3 and the linker histone H1) are brought together with genomic DNA to form chromatin. The specific focus of this proposal is the characterization of a class of enzymes known as type B histone acetyltransferases. These enzymes are responsible for the post-translational acetylation of newly synthesized histones. While it has been known for decades that newly synthesized histones are acetylated during the process of chromatin assembly, the function of these modifications is not known. We have proposed a number of studies that will help to identify the role of the type B histone acetyltransferase Hat1p in chromatin assembly. The first specific aim utilizes S. cerevisiae as a model system to study Hat1p and the acetylation of newly synthesized histones. We will use experimental systems that will allow us to directly assay for the effect of Hat1p on chromatin assembly in several different contexts. In addition, will use a variety of yeast molecular genetic techniques to decipher the unique and overlapping functions of the multiple sites of acetylation that have been identified on newly synthesized histones. Finally, we will continue the isolation and characterization of a novel chromatin assembly factor that we have identified in yeast extracts. The second specific aim extends our studies of the yeast enzyme, to the characterization of mammalian Hat1. We will use biochemical techniques to isolate and characterize complexes containing the human Hat1 enzyme. In addition, we will characterize a Hat1 mouse knockout model in order to identify the function of this type B histone acetyltransferase in a complex organism.
Eukaryotic cells contain an enormous linear length of DNA that must be highly condensed to be packaged inside cells. This packaging results from the formation of a structure known as chromatin that plays an important role in regulating most processes that occur in the nucleus. The importance of chromatin structure is evidenced by the numerous examples of defects in chromatin structure that cause serious human diseases. This proposal seeks to understand the mechanisms by which chromatin is assembled and regulated which will aid in our understanding and treatment of these diseases.
|Zhang, Pei; Branson, Owen E; Freitas, Michael A et al. (2016) Identification of replication-dependent and replication-independent linker histone complexes: Tpr specifically promotes replication-dependent linker histone stability. BMC Biochem 17:18|
|Bernier, Morgan; Luo, Yi; Nwokelo, Kingsley C et al. (2015) Linker histone H1 and H3K56 acetylation are antagonistic regulators of nucleosome dynamics. Nat Commun 6:10152|
|Singh, Rajbir; Harshman, Sean W; Ruppert, Amy S et al. (2015) Proteomic profiling identifies specific histone species associated with leukemic and cancer cells. Clin Proteomics 12:22|
|Guan, Xiaoyan; Rastogi, Neha; Parthun, Mark R et al. (2014) SILAC peptide ratio calculator: a tool for SILAC quantitation of peptides and post-translational modifications. J Proteome Res 13:506-16|
|Li, Yang; Zhang, Li; Liu, Tingting et al. (2014) Hat2p recognizes the histone H3 tail to specify the acetylation of the newly synthesized H3/H4 heterodimer by the Hat1p/Hat2p complex. Genes Dev 28:1217-27|
|Knapp, Amy R; Wang, Huanyu; Parthun, Mark R (2014) The yeast histone chaperone hif1p functions with RNA in nucleosome assembly. PLoS One 9:e100299|
|Ge, Zhongqi; Nair, Devi; Guan, Xiaoyan et al. (2013) Sites of acetylation on newly synthesized histone H4 are required for chromatin assembly and DNA damage response signaling. Mol Cell Biol 33:3286-98|
|Nagarajan, Prabakaran; Ge, Zhongqi; Sirbu, Bianca et al. (2013) Histone acetyl transferase 1 is essential for mammalian development, genome stability, and the processing of newly synthesized histones H3 and H4. PLoS Genet 9:e1003518|
|Harshman, Sean W; Young, Nicolas L; Parthun, Mark R et al. (2013) H1 histones: current perspectives and challenges. Nucleic Acids Res 41:9593-609|
|Guan, Xiaoyan; Rastogi, Neha; Parthun, Mark R et al. (2013) Discovery of histone modification crosstalk networks by stable isotope labeling of amino acids in cell culture mass spectrometry (SILAC MS). Mol Cell Proteomics 12:2048-59|
Showing the most recent 10 out of 29 publications