We have analyzed human centromeric chromatin containing CENPA from HeLa cells in culture using Chromatin IP followed by atomic force microscopy measurements and mass spectrophotometry. Thus far, we have identified that the CENPA chromatin structure is uniquely organized during interphase, and has fundamentally different characteristics from the rest of the chromatin which packages the genome. We plan to extend our analysis using live imaging coupled with AFM across the cell cycle to address how CENP-A is assembled and retained, as well as how it participates in non-centromeric functions at ectopic loci. We have discovered that CENP-A changes its structure over the cell cycle. This manuscript has been published in the journal Cell in August 2012 and was highlighted in Cell and Nature Reviews. A follow up has been published in the journal Nucleus in January 2013, and a current correspondence on the matter has been invited by the editors of Nature Structure Molecular Biology and is currently under review.

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National Cancer Institute (NCI)
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National Cancer Institute Division of Basic Sciences
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Walkiewicz, Marcin P; Dimitriadis, Emilios K; Dalal, Yamini (2014) CENP-A octamers do not confer a reduction in nucleosome height by AFM. Nat Struct Mol Biol 21:2-3
Volle, Catherine; Dalal, Yamini (2014) Histone variants: the tricksters of the chromatin world. Curr Opin Genet Dev 25:8-14,138
Quénet, Delphine; Dalal, Yamini (2014) A long non-coding RNA is required for targeting centromeric protein A to the human centromere. Elife 3:e03254
Dalal, Yamini; McNally, James G (2014) Now you see it, now you don't: a biochemist's primer for advances in high-resolution microscopy: comment on "Biomolecular dynamics and binding studies in the living cell" by Stephan Diekmann and Christian Hoischen. Phys Life Rev 11:36-7; discussion 38
Bui, Minh; Walkiewicz, Marcin P; Dimitriadis, Emilios K et al. (2013) The CENP-A nucleosome: a battle between Dr Jekyll and Mr Hyde. Nucleus 4:37-42