title: Phosphorylation of mitochondrial polyubiquitin by PINK1 promotes Parkin mitochondrial tethering.
abstract: The kinase PINK1 and the E3 ubiquitin (Ub) ligase Parkin participate in mitochondrial quality control. The phosphorylation of Ser65 in Parkin's ubiquitin-like (UBl) domain by PINK1 stimulates Parkin activation and translocation to damaged mitochondria, which induces mitophagy generating polyUb chain. However, Parkin Ser65 phosphorylation is insufficient for Parkin mitochondrial translocation. Here we report that Ser65 in polyUb chain is also phosphorylated by PINK1, and that phosphorylated polyUb chain on mitochondria tethers Parkin at mitochondria. The expression of Tom70MTS-4xUb SE, which mimics phospho-Ser65 polyUb chains on the mitochondria, activated Parkin E3 activity and its mitochondrial translocation. An E3-dead form of Parkin translocated to mitochondria with reduced membrane potential in the presence of Tom70(MTS)-4xUb SE, whereas non-phospho-polyUb mutant Tom70(MTS)-4xUb SA abrogated Parkin translocation. Parkin binds to the phospho-polyUb chain through its RING1-In-Between-RING (IBR) domains, but its RING0-linker is also required for mitochondrial translocation. Moreover, the expression of Tom70(MTS)-4xUb SE improved mitochondrial degeneration in PINK1-deficient, but not Parkin-deficient, Drosophila. Our study suggests that the phosphorylation of mitochondrial polyUb by PINK1 is implicated in both Parkin activation and mitochondrial translocation, predicting a chain reaction mechanism of mitochondrial phospho-polyUb production by which rapid translocation of Parkin is achieved.
authors.affiliation: Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Kahori
authors.initials: K
authors.lastname: Shiba-Fukushima
authors.affiliation: Department of Research for Parkinson's Disease, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Arano
authors.affiliation: Department of Neuroscience for Neurodegenerative Disorders, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Matsumoto
authors.affiliation: Department of Research for Parkinson's Disease, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Inoshita
authors.affiliation: Department of Molecular and Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Yoshida
authors.affiliation: Department of Molecular and Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ishihama
authors.affiliation: Department of Life Science, University of Seoul, Seoul, Korea.
authors.forename: Kwon-Yul
authors.initials: KY
authors.lastname: Ryu
authors.affiliation: Department of Neuroscience for Neurodegenerative Disorders, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Nukina
authors.affiliation: Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan; Department of Research for Parkinson's Disease, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Hattori
authors.affiliation: Department of Research for Parkinson's Disease, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Imai
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002478:Cells, Cultured; D004330:Drosophila; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D010766:Phosphorylation; D025821:Polyubiquitin / Q000378:metabolism*; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism*; D021381:Protein Transport; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D054875:Ubiquitination; D000099202:PTEN-Induced Putative Kinase
chemical_list: D025821:Polyubiquitin; D011494:Protein Kinases; D044767:Ubiquitin-Protein Ligases; D000099202:PTEN-Induced Putative Kinase; C111567:parkin protein