Download MendeleyPromotion of RNF168-Mediated Nucleosomal H2A Ubiquitylation by Structurally Defined K63-Polyubiquitylated Linker Histone H1.
Shi, Q., Deng, Z., Zhang, L., Tong, Z., Li, J.B., Chu, G.C., Ai, H., Liu, L.(2025) Angew Chem Int Ed Engl 64: e202413651-e202413651
- PubMed: 39363740
- DOI: https://doi.org/10.1002/anie.202413651
- Primary Citation of Related Structures:
9IPU - PubMed Abstract:
The chemical synthesis of histones with homogeneous modifications is a powerful approach for quantitatively deciphering the functional crosstalk between different post-translational modifications (PTMs). In this study, we developed an expedient site-specific (poly)ubiquitylation strategy (CAEPL, Cysteine Aminoethylation coupled with Enzymatic Protein Ligation), which integrates the Cys-aminoethylation reaction with the process of ubiquitin-activating enzyme UBA1-assisted native chemical ligation. Using this strategy, we successfully prepared monoubiquitylated and K63-linked di- and tri-ubiquitylated linker histone H1.0 proteins, which were incorporated into individual chromatosomes. Quantitative biochemical analysis of different RNF168 constructs on H1 ubiquitylated chromatosomes with different ubiquitin chain lengths demonstrated that K63-linked polyubiquitylated H1.0 could directly stimulate RNF168 ubiquitylation activity by enhancing the affinity between RNF168 and the chromatosome. Subsequent cryo-EM structural analysis of the RNF168/UbcH5c-Ub/H1.0-K63-Ub 3 chromatosome complex revealed the potential recruitment orientation between RNF168 UDM1 domain and K63-linked ubiquitin chain on H1.0. Finally, we explored the impact of H1.0 ubiquitylation on RNF168 activity in the context of asymmetric H1.0-K63-Ub 3 di-nucleosome substrate, revealing a comparable stimulation effect of both the inter- and intra-nucleosomal crosstalk. Overall, our study highlights the significance of access to structurally defined polyubiquitylated H1.0 by the CAEPL strategy, enabling in-depth mechanistic investigations of in-trans PTM crosstalk between linker histone H1.0 and core histone H2A ubiquitylation.
Organizational Affiliation:
New Cornerstone Science Laboratory, Tsinghua-Peking Joint Center for Life Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China.
