title: Disruption of the autoinhibited state primes the E3 ligase parkin for activation and catalysis.
abstract: The PARK2 gene is mutated in 50% of autosomal recessive juvenile parkinsonism (ARJP) cases. It encodes parkin, an E3 ubiquitin ligase of the RBR family. Parkin exists in an autoinhibited state that is activated by phosphorylation of its N-terminal ubiquitin-like (Ubl) domain and binding of phosphoubiquitin. We describe the 1.8 Å crystal structure of human parkin in its fully inhibited state and identify the key interfaces to maintain parkin inhibition. We identify the phosphoubiquitin-binding interface, provide a model for the phosphoubiquitin-parkin complex and show how phosphorylation of the Ubl domain primes parkin for optimal phosphoubiquitin binding. Furthermore, we demonstrate that the addition of phosphoubiquitin leads to displacement of the Ubl domain through loss of structure, unveiling a ubiquitin-binding site used by the E2~Ub conjugate, thus leading to active parkin. We find the role of the Ubl domain is to prevent parkin activity in the absence of the phosphorylation signals, and propose a model for parkin inhibition, optimization for phosphoubiquitin recruitment, release of inhibition by the Ubl domain and engagement with an E2~Ub conjugate. Taken together, this model provides a mechanistic framework for activating parkin.
authors.affiliation: MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK.
authors.forename: Atul
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Department of Biochemistry, Schulich School of Medicine & Dentistry University of Western Ontario, London, ON, Canada.
authors.forename: Jacob D
authors.initials: JD
authors.lastname: Aguirre
authors.affiliation: Department of Biochemistry, Schulich School of Medicine & Dentistry University of Western Ontario, London, ON, Canada.
authors.forename: Tara E C
authors.initials: TE
authors.lastname: Condos
authors.affiliation: MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK.
authors.forename: R Julio
authors.initials: RJ
authors.lastname: Martinez-Torres
authors.affiliation: MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK.
authors.forename: Viduth K
authors.initials: VK
authors.lastname: Chaugule
authors.affiliation: MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK.
authors.forename: Rachel
authors.initials: R
authors.lastname: Toth
authors.affiliation: Centre for Gene Regulation and Expression, College of Life Sciences University of Dundee, Dundee, UK.
authors.forename: Ramasubramanian
authors.initials: R
authors.lastname: Sundaramoorthy
authors.affiliation: Department of Biochemistry, Schulich School of Medicine & Dentistry University of Western Ontario, London, ON, Canada.
authors.forename: Pascal
authors.initials: P
authors.lastname: Mercier
authors.affiliation: MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK.
authors.forename: Axel
authors.initials: A
authors.lastname: Knebel
authors.affiliation: Department of Biochemistry, Schulich School of Medicine & Dentistry University of Western Ontario, London, ON, Canada.
authors.forename: Donald E
authors.initials: DE
authors.lastname: Spratt
authors.affiliation: Department of Biochemistry, Schulich School of Medicine & Dentistry University of Western Ontario, London, ON, Canada.
authors.forename: Kathryn R
authors.initials: KR
authors.lastname: Barber
authors.affiliation: Department of Biochemistry, Schulich School of Medicine & Dentistry University of Western Ontario, London, ON, Canada gshaw1@uwo.ca h.walden@dundee.ac.uk.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Shaw
authors.affiliation: MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK gshaw1@uwo.ca h.walden@dundee.ac.uk.
authors.forename: Helen
authors.initials: H
authors.lastname: Walden
mesh_terms: D001665:Binding Sites / Q000235:genetics; D002151:Calorimetry; D002384:Catalysis; D002850:Chromatography, Gel; D003460:Crystallization; D004789:Enzyme Activation / Q000235:genetics*; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D010766:Phosphorylation; D011487:Protein Conformation; D025801:Ubiquitin / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D025801:Ubiquitin; D044767:Ubiquitin-Protein Ligases; C111567:parkin protein
keywords: Parkinson's disease; enzyme mechanism; phosphorylation; ubiquitin ligase; ubiquitination