Biological Sciences

Profile

I have been playing with histones since they were first purified in the early ‘60s.  Defining the domain structure of core and linker histones by NMR and limited proteolysis was the first step.  I claim to have been the principal midwife at the birth of chromatin IPs that use antibodies to modified histones. I continue to marvel at the ever-widening role of histones in controlling the genome.

The conviction that proteins and their complexes with nucleic acids cannot be regarded simply as black boxes with known inputs and outputs drives studies of their structures and energetics.  This has involved the use of NMR, micro-calorimetry and fluorescence techniques.

Research Interests

• Chromatin structure and function.
• Protein/nucleic acid interactions and structures.
• Genetic pre-disposition to breast cancer.

Recent Publications

More recent publications

Research interests: Chromatin structure and function.

1. Epigenetic Mapping

Post-translational modifications of histones (e.g. acetylation, methylation, phosphorylation,  ubiquitination) and primary sequence variants of histones H2A and H3 play key roles in the control of gene expression. They constitute epigenetic information central to defining the state of cellular differentiation. We use the Chromatin Immuno-Precipitation (ChIP) assay, both ‘native’ and ‘crosslinked’, to map the spatial distribution of these chromosomal marks in cells of various types. The same approach is used to map the HMG architectural transcription factors.

A recent example was a joint project with the Zhao lab at NIH to map the variant histone H2A.Z in mouse embryonic stem cells. This demonstrated its presence at the transcriptional start sites of both active and bivalent genes, as well as at enhancers and insulators.  Such a widespread presence at cis-control elements is best explained by a universal role for H2A.Z in manipulating chromatin structure to permit access of a broad range of transcription factor complexes. This model of H2A.Z function is being tested in the reprogramming of fibroblasts to pluripotent cells.

Recent publications

Hu, G., Cui, K., Northrup, D., Liu, C., Wang, C., Tang, Q., Ge, K., Levens, D., Crane-Robinson, C. and Zhao, K. (2012) H2A.Z facilitates access of active and repressive complexes to chromatin in embryonic stem cell self-renewal and differentiation. Cell Stem Cell, 12, 1-13. ISSN 1934-5909 10.1016/j.stem.2012.11.003

Staynov, D. and Crane-Robinson, C. (2011) Chromatin structure at active genes. The FEBS Journal, 278, 2181. ISSN 1742-4658 10.1111/j.1742-4658.2011.08152.x

Trollope, A, Sapojnikova, N, Thorne, A, Crane-Robinson, C and Myers, F. (2010) Linker histone subtypes are not generalized gene repressors. Biochim. Biophys. Acta, 1799, 642-652. ISSN 0006-3002 10.1016/j.bbagrm.2010.08.007.

Sapojnikova, N., Thorne, A., Myers, F., Staynov, D. and Crane-Robinson, C. (2009) The chromatin of active genes is not in a permanently open conformation.  J Mol Biol, 386, 290-299. ISSN 0022-2836 10.1016/j.jmb.2008.12.048

Myers, F., Lefevre, P., Mantouvalou, E., Bruce, K., Lacroix, C., Bonifer, C., Thorne, A. and Crane-Robinson, C. (2006) Developmental activation of the lysozyme gene in chicken macrophage cells is linked to core histone acetylation at its enhancer elements. Nucleic Acids Res, 34, 4025-4035. ISSN 1362-4962 10.1093/nar/gkl543

Bruce K., Myers F.A., Mantouvalou E., Lefevre P., Greaves I., Bonifer C., Tremethick D.J., Thorne A.W., Crane-Robinson C. (2005) The replacement histone H2A.Z in a hyperacetylated form is a feature of active genes in the chicken.  Nucleic Acids Res. 33, 5633-9.

2. Energetics of protein-DNA interactions

The forces driving the formation of complexes between the DNA binding domains of eukaryotic transcription factors and their duplex DNA targets have been studied in considerable detail in collaboration with the lab of Peter Privalov at Johns Hopkins University. It turns out that binding to the minor groove involves a different energetic strategy to major groove binding. In particular, release of ordered water from the AT-rich minor groove yields an entropy increase large enough to drive the interaction and compensate for unfavourable enthalpic contributions. In contrast, major groove binding is driven both by favourable enthalpic as well as entropic forces.

A new project in the lab is to precisely reconstitute the chromatosome – the fundamental repeating unit of chromatin that contains a molecule of linker histone in addition to the 4 core histones – with a view to studying its structure by a variety of biophysical methods.

Recent publications

Shukla, H., Vaitiekunas, P., Majumdar, A., Dragan, A., Dimitriadis, E., Kotova, S., Crane-Robinson, C. and Privalov, P.L. (2012) The linker of the interferon response factor 3 transcription factor is not unfolded. Biochemistry, 51, 6320-6327. ISSN 0006-2960 10.1021/bi300260s

Pivalov, P.L. , Dragan, A. and Crane-Robinson, C. (2011) Interpreting protein/DNA interactions: distinguishing specific from non-specific and electrostatic from non-electrostatic components. Nucleic Acids Res, 39, 2483-2491. ISSN 0305-1048 10.1093/nar/gkq984

Privalov, P.L., Dragan, A. and Crane-Robinson, C. (2009) The cost of DNA bending. Trends in Biochemical Sciences, 34, 464-470. ISSN 0968-0004 10.1016/j.tibs.2009.05.005.

Crane-Robinson, C., Dragan, A. and Read, C. (2009) Defining the thermodynamics of protein/DNA complexes and their components using micro-calorimetry. In: DNA-protein interactions principles and protocols. Methods in Molecular Biology, 543, 625-651. Humana Press, New York, ISBN 9781603270144

Privalov, P., Dragan, A., Crane-Robinson, C, Breslauer, K., Remeta, D. and Minetti, C. (2007) What drives proteins into the major or minor grooves of DNA? J Mol Biol, 365, 1-9. ISSN 0022-2836 10.1016/j.jmb.2006.09.059

Crane-Robinson, C., Dragan, A. and Privalov, P. (2006) The extended arms of DNA-binding domains: a tale of tails. Trends in Biochemical Sciences, 31, 547-552. ISSN 0968-0004 10.1016/j.tibs.2006.08.006

Dragan, A., Li, Z., Makeyeva, E., Milgotina, E., Liu, Y., Crane-Robinson, C. and Privalov, P. (2006) Forces Driving the Binding of Homeodomains to DNA. Biochemistry, 45, 141-151. ISSN 0006-2960 10.1021/bi051705m