NuRD complex assembly

NuRD complex assembly The nucleosome remodeling and deacetylase (NuRD) complex is a multi-protein ATP-dependent chromatin remodeler that, uniquely, combines histone deacetylase activity with ATPase and DNA translocase activities (Tong et al, 1998; Xue et al, 1998; reviewed in Alendar and Berns, 2021; Boulasiki et al, 2023; Eustermann et al, 2024). In humans, the ATPase activity is provided by one of three CHD proteins, CHD3, CHD4 or CHD5, each of which assemble into NuRD complexes with overlapping but distinct composition and roles (Le Guezennec et al, 2006; Kolla et al, 2015; Nitarska et al, 2016; reviewed in Alendar and Berns, 2021; Asmamaw et al, 2024). Histone deacetylase activity is contributed by either HDAC1 or HDAC2 (Zhang et al, 1999). In addition, the NuRD complex contains five additional core components, each of which exists in humans as members of paralogous protein families: metastasis-associated protein 1 (MTA1), MTA2 or MTA3; RBBP4 or RBBP7; methyl-CpG-binding domain protein 2 (MBD2) or MBD3; GATAD2A or GATAD2B; and cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) or CDK2AP2 (reviewed in Alendar and Berns, 2021; Boulasiki et al, 2023; Asmamaw et al, 2024). NuRD complex assembly is thought to nucleate around a core complex consisting of HDAC1/2, MTA1/2/3 and RBBP4/7, to which the other subunits are then recruited (reviewed in Boulasiki et al, 2023; Asmamaw et al, 2024). The compositional diversity of NuRD complexes has made categorically defining complex stoichiometry and structure challenging, so although numerous structures of individual components or subcomplexes have been solved, no complete structure exists. Although NuRD complexes were initially identified as transcriptional repressors, it is now appreciated that they can act as activators as well (Williams et al, 2004; Bornelov et al, 2018; reviewed in Alendar and Berns, 2021). Although many components of the complex are able to interact with DNA and/or histones, recruitment of NuRD to target genes is predominantly mediated by interaction with transcription factors (reviewed in Alendar and Berns, 2021; Asmamaw et al, 2024);
In addition to being part of the NuRD complex, subfamily II CHD proteins may also be part of other chromatin modifying complexes, such as the CHD4-ChADH complex (Kaaij et al, 2019), and have indeed been shown to have chromatin sliding activity in vitro in the absence of interacting protein partners (Zhong et al, 2020; reviewed in Boulasiki et al, 2023; Alendar and Berns, 2021).