Molecular analysis of human gene regulation

Abstract

The data presented in this Thesis work towards understanding the heterogeneity of the nucleosome remodelling and deacetylase (NuRD) complex, a multi-subunit complex with deacetylase and remodeling activities. The NuRD complex does not have any sequence-specific DNA-binding domains yet is recruited ­­­­­to specific genomic locations to mediate fundamental DNA-templated processes. Currently, our understanding of how the NuRD complex chooses its genomic target sites is limited. This project aimed to explore the interactions made by the NuRD complex with coregulatory proteins that themselves are capable of interacting with chromatin and imparting specificity to the NuRD complex. Understanding the mechanisms by which such proteins interact with the NuRD complex will help us build a mechanistic picture of how the NuRD complex selects its genomic targets and may offer opportunities to regulate NuRD function. Although many interaction partners of the NuRD complex have been reported, the data are mostly limited to mass spectrometry and co-immunoprecipitation assays and lack structural analyses of the interactions. Also, the rules governing the interaction of the NuRD complex with other proteins to achieve specificity have proven difficult to define due to the complexity of the NuRD complex. The research in this thesis details the characterization of the interaction between NuRD and three chromatin-associated proteins, namely PWWP2A, ZMYND8 and CASZ1b, to understand the functional specificity governed by the NuRD complex. Investigating the assembly of the NuRD complex concerning its interacting proteins will allow insight into the mechanism of gene regulation.