title: Parkin-catalyzed ubiquitin-ester transfer is triggered by PINK1-dependent phosphorylation.
abstract: PINK1 and PARKIN are causal genes for autosomal recessive familial Parkinsonism. PINK1 is a mitochondrial Ser/Thr kinase, whereas Parkin functions as an E3 ubiquitin ligase. Under steady-state conditions, Parkin localizes to the cytoplasm where its E3 activity is repressed. A decrease in mitochondrial membrane potential triggers Parkin E3 activity and recruits it to depolarized mitochondria for ubiquitylation of mitochondrial substrates. The molecular basis for how the E3 activity of Parkin is re-established by mitochondrial damage has yet to be determined. Here we provide in vitro biochemical evidence for ubiquitin-thioester formation on Cys-431 of recombinant Parkin. We also report that Parkin forms a ubiquitin-ester following a decrease in mitochondrial membrane potential in cells, and that this event is essential for substrate ubiquitylation. Importantly, the Parkin RING2 domain acts as a transthiolation or acyl-transferring domain rather than an E2-recruiting domain. Furthermore, formation of the ubiquitin-ester depends on PINK1 phosphorylation of Parkin Ser-65. A phosphorylation-deficient mutation completely inhibited formation of the Parkin ubiquitin-ester intermediate, whereas phosphorylation mimics, such as Ser to Glu substitution, enabled partial formation of the intermediate irrespective of Ser-65 phosphorylation. We propose that PINK1-dependent phosphorylation of Parkin leads to the ubiquitin-ester transfer reaction of the RING2 domain, and that this is an essential step in Parkin activation.
authors.affiliation: Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Iguchi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kujuro
authors.forename: Kei
authors.initials: K
authors.lastname: Okatsu
authors.forename: Fumika
authors.initials: F
authors.lastname: Koyano
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Kosako
authors.forename: Mayumi
authors.initials: M
authors.lastname: Kimura
authors.forename: Norihiro
authors.initials: N
authors.lastname: Suzuki
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Uchiyama
authors.forename: Keiji
authors.initials: K
authors.lastname: Tanaka
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Matsuda
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000235:genetics; D055162:Biocatalysis; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002478:Cells, Cultured; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology; D004952:Esters / Q000737:chemistry / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D018345:Mice, Knockout; D008954:Models, Biological; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D061209:Proton Ionophores / Q000494:pharmacology; D012694:Serine / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D025801:Ubiquitin / Q000737:chemistry / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination; D000099202:PTEN-Induced Putative Kinase
chemical_list: D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D003545:Cysteine; D004952:Esters; D011494:Protein Kinases; D061209:Proton Ionophores; D012694:Serine; D025801:Ubiquitin; D044767:Ubiquitin-Protein Ligases; D000099202:PTEN-Induced Putative Kinase; C111567:parkin protein
keywords: Mitochondria; Parkin; Pink1; RING Finger; Ubiquitin; Ubiquitin Ligase