Chromatin was first defined by Flemming in 1882 as the 'substance in the cell nucleus which is readily Stained'that "is retractile to digestion'. The term stuck, and now is taken to refer to DNA (the readily stained component) and the associated proteins that make it retractile to digestion. Over the past two decades, it has become apparent that the associated proteins play a key role in regulating transcription, replication and recombination ofthe DNA. The basic structural component of chromatin, the nucleosome, which was treated for years as a 'dumb'building block, has been shown to be dynamic and regulated at several levels. Nucleosomes can be evicted or shifted in position by ATP-dependent remodeling proteins, opening up DNA sequences. They can be covalently modified in different ways, allowing differential abilities to interact with the regulatory machinery. The purpose ofthe experiments described in this application is to characterize regulatory proteins that modulate chromatin structure to effect gene regulation. The three Aims examine three separate complexes involved in these processes, all of which are human homologs of proteins originally identified in screens done in Drosophila for mutations that impact developmental progression. These screens identified the Polycomb-Group (PcG) of genes, responsible for maintaining repression of master regulatory genes during development, and the trithorax-Group (trxG), isolated as suppressor of a Polycomb mutant.
Aims 1 and 2 examine two mammalian ATP-dependent remodeling proteins in the trxG family and Aim 3 examines a mammalian protein in the PcG family.
Aim 1 will determine the crystal structure of the ATPase domain of BRG1;
Aim 2 will examine the impact of human disease mutations of function of the CHD7-ATP-dependent r

Public Health Relevance

The CHD7 gene is mutated in 90% of human patients that have CHARGE syndrome, a serious developmental defect that impact 1 in 10,000 live births. EZH2 has been implicated in numerous human malignancies and is a key therapeutic target in cancer treatment. BRGI and other members ofthe human SWI/SNF family complexes are also strongly implicated in numerous cancers. PROJECT/PERFORIIMNCE SITE(S) (if additional space is needed, use Project/Perfomnance Site Fonnat Page) Pix>ject/Performance Site Primary Location Organizational Name: Massachusetts General Hospital DUNS: 07-313-0411 streeti: 185 Cambridge Street street 2: City: Boston County: state: MA Province: Country: U S A Zip/Postal Code: 0 2 1 1 4

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Method to Extend Research in Time (MERIT) Award (R37)
Project #
Application #
Study Section
Special Emphasis Panel (NSS)
Program Officer
Carter, Anthony D
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Massachusetts General Hospital
United States
Zip Code
Bowman, Sarah K; Deaton, Aimee M; Domingues, Heber et al. (2014) H3K27 modifications define segmental regulatory domains in the Drosophila bithorax complex. Elife 3:e02833
Kingston, Robert E; Tamkun, John W (2014) Transcriptional regulation by trithorax-group proteins. Cold Spring Harb Perspect Biol 6:a019349
West, Jason A; Davis, Christopher P; Sunwoo, Hongjae et al. (2014) The long noncoding RNAs NEAT1 and MALAT1 bind active chromatin sites. Mol Cell 55:791-802
West, Jason A; Cook, April; Alver, Burak H et al. (2014) Nucleosomal occupancy changes locally over key regulatory regions during cell differentiation and reprogramming. Nat Commun 5:4719
Sexton, Brittany S; Avey, Denis; Druliner, Brooke R et al. (2014) The spring-loaded genome: nucleosome redistributions are widespread, transient, and DNA-directed. Genome Res 24:251-9
Ho, Joshua W K; Jung, Youngsook L; Liu, Tao et al. (2014) Comparative analysis of metazoan chromatin organization. Nature 512:449-52
Riedel, Christian G; Dowen, Robert H; Lourenco, Guinevere F et al. (2013) DAF-16 employs the chromatin remodeller SWI/SNF to promote stress resistance and longevity. Nat Cell Biol 15:491-501
Robine, Nicolas; Lau, Nelson C; Balla, Sudha et al. (2009) A broadly conserved pathway generates 3'UTR-directed primary piRNAs. Curr Biol 19:2066-76
Mahajan, Milind C; Narlikar, Geeta J; Boyapaty, Gokul et al. (2005) Heterogeneous nuclear ribonucleoprotein C1/C2, MeCP1, and SWI/SNF form a chromatin remodeling complex at the beta-globin locus control region. Proc Natl Acad Sci U S A 102:15012-7