The biological functions of the histone modification H3K64me1 and the novel human-specific H3 variant H3.X

• Applicant: Professorin Dr. Sandra Brigitte Hake
• Subject Area: General Genetics and Functional Genome Biology
• Term: from 2007 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 42819898

Posttranslational modifications (PTMs) of histones and the incorporation of histone variants might alter the structure of chromatin, thereby regulating gene transcription. In the first part of our study, we will investigate the biological function of a novel histone H3 PTM; monomethylation of lysine 64 (H3K64me1). With the help of H3K64me1-specific antibodies we plan to investigate: (1) the presence of this mark in different organisms, (2) the sub-nuclear and chromosomal localization of H3K64me1 and (3) the impact of H3K64me1 on gene regulation. Furthermore, we plan to identify proteins that specifically associate with H3K64me1 by peptide-pull down assays. In a second project, we will investigate a novel human-specific histone H3 variant, which we named H3.X. Initial experiments demonstrated that H3.X mRNA is expressed in a human osteosarcoma cell line and that tagged H3.X protein is localized to the nucleus and incorporated into chromatin. Our aim is to characterize the function of H3.X in detail. First, we will analyze the expression of H3.X mRNA in different cell types/tissues by northern blot analysis. Secondly, we will use mass spectrometry to verify endogenous H3.X protein expression and to search for PTMs. Thirdly, we want to analyze cell-cycle dependent expression profiles of H3.X and the chaperone complex which is responsible for chromatin-incorporation of H3.X. Finally, we will investigate the role of H3.X in gene expression regulation by ChIP.

• DFG Programme: Research Grants