Prp19/Pso4 Is an Autoinhibited Ubiquitin Ligase Activated by Stepwise Assembly of Three Splicing Factors

• DOI: 10.1016/j.molcel.2018.02.022
• Publication Date: 2018-03-15T15:45:33Z
• Authors: Tales Rocha de Moura; Sina Mozaffari-Jovin; Csaba Zoltán Kibé...; Jana Schmitzová; Olexandr Dybkov; Constantin Cretu; Michael Kachala; Dmitri Svergun; Henning Urlaub; Reinhard Lührmann; Vladimir Pena
• Keywords: Models, Molecular; 0303 health sciences; Protein Conformation; Intracellular Signaling Peptides and Proteins; Nuclear Proteins; RNA-Binding Proteins; Cell Cycle Proteins; Spodoptera; Neoplasm Proteins; Structure-Activity Relationship; 03 medical and health sciences; DNA Repair Enzymes; HEK293 Cells; Replication Protein A; Mutation; Sf9 Cells; Animals; Humans; RNA Splicing Factors; Crystallization; info:eu-repo/classification/ddc/610; DNA Damage; HeLa Cells

Human nineteen complex (NTC) acts as a multimeric E3 ubiquitin ligase in DNA repair and splicing. The transfer of ubiquitin is mediated by Prp19-a homotetrameric component of NTC whose elongated coiled coils serve as an assembly axis for two other proteins called SPF27 and CDC5L. We find that Prp19 is inactive on its own and have elucidated the structural basis of its autoinhibition by crystallography and mutational analysis. Formation of the NTC core by stepwise assembly of SPF27, CDC5L, and PLRG1 onto the Prp19 tetramer enables ubiquitin ligation. Protein-protein crosslinking of NTC, functional assays in vitro, and assessment of its role in DNA damage response provide mechanistic insight into the organization of the NTC core and the communication between PLRG1 and Prp19 that enables E3 activity. This reveals a unique mode of regulation for a complex E3 ligase and advances understanding of its dynamics in various cellular pathways.