Analysis of chromatin targeting modules in the chromatin remodelling enzyme NURF

Jang, Boyun (2014). Analysis of chromatin targeting modules in the chromatin remodelling enzyme NURF. University of Birmingham. Ph.D.

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Abstract

Drosophila nucleosome remodelling factor (NURF) is one of the founding members of the ISWI family of ATP-dependent chromatin remodelling enzymes and mediates energy-dependent nucleosome sliding leading to transcription regulation. In previous work (Wysocka et al., 2006), NURF was shown to be recruited to gene targets by binding specific histone modifications. The largest subunit of NURF, NURF301, contains a bromodomain and three PHD finger domains that have the ability to recognize specific histone modifications. Here we determine the histone binding-specificities of these domains, and how NURF histone binding is influenced by histone modification "cross-talk". This has been analyzed by histone peptide library array assays and our study shows that the PHD2 domain specifically recognizes the histone H3K4me3 mark. This binding can be inhibited by phosphorylation of H3 Thr 3, while enhanced by acetylation of H3 Lys 9 and phosphorylation of Ser 10. The binding specificities of bromodomain, PHD and PHD1 domains were also determined. These data were confirmed by peptide pull-down, Biacore and immunofluorescence microscopy assays. Moreover, two different NURF301-A/B and NURF301-C isoforms were CTAP-tagged by recombineering, and we used chromatin immunoprecipitation coupled sequencing (ChIP-Seq) to profile the genome-wide distribution of NURF in vivo. Therefore, our results identify regulatory mechanisms of histone modifications directing recruitment of ATP-dependent chromatin remodelling enzymes.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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