We have a long-standing interest in histone analysis. Our Chromatin Oncobiology and DNA-Damage subgroup continues to dig deeper into the "histone code", a complex mixture of post-translational modifications that together determine a host of cellular processes. We are interested in visualizing dynamic histone PTM changes simultaneously on multiple sites. Through application of technology developed in our Top Down Proteomics subgroup, we are able to apply "Precision Proteomics" to histone analysis.
Packaging DNA (read more here)
a, The organization of DNA within the chromatin structure. The lowest level of organization is the nucleosome, in which two superhelical turns of DNA (a total of 165 base pairs) are wound around the outside of a histone octamer. Nucleosomes are connected to one another by short stretches of linker DNA. At the next level of organization the string of nucleosomes is folded into a fibre about 30 nm in diameter, and these fibres are then further folded into higher-order structures. At levels of structure beyond the nucleosome the details of folding are still uncertain. (Redrawn from ref. 41, with permission).
Post-Translational Modifications with Changes in Cellular State (read more here)
Identification of H2A.X in asynchronous and m-phase arrested HeLa. An increase in phosphorylation can be seen during m-phase arrest (red peak). Confocal microscopy images were also taken at each cellular state, staining with the antibody of phosphorylated H2A.X. An increase in phosphorylation in the m-phase arrested cells is also seen through microscopy.
Profiling of Mammalian Cells (read more here)
a, Online LC-MS chromatogram of oxidized histone extract b, MS data of histones H2B, H4, H2A and H3, obtained using a 7T LTQ FT. Acetylation forms are labelled. Histone H3 shows increased acetylation.