title: PKA Regulates PINK1 Stability and Parkin Recruitment to Damaged Mitochondria through Phosphorylation of MIC60.
abstract: A mitochondrial kinase, PTEN-induced putative kinase 1 (PINK1), selectively recruits the ubiquitin ligase Parkin to damaged mitochondria, which modifies mitochondria by polyubiquitination, leading to mitochondrial autophagy. Here, we report that treatment with an adenylate cyclase agonist or expression of protein kinase A (PKA) impairs Parkin recruitment to damaged mitochondria and decreases PINK1 protein levels. We identified a mitochondrial membrane protein, MIC60 (also known as mitofilin), as a PKA substrate. Mutational and mass spectrometric analyses revealed that the Ser528 residue of MIC60 undergoes PKA-dependent phosphorylation. MIC60 transiently interacts with PINK1, and MIC60 downregulation leads to a reduction in PINK1 and mislocalization of Parkin. Phosphorylation-mimic mutants of MIC60 fail to restore the defect in Parkin recruitment in MIC60-knocked down cells, whereas a phosphorylation-deficient MIC60 mutant facilitates the mitochondrial localization of Parkin. Our findings indicate that PKA-mediated phosphorylation of MIC60 negatively regulates mitochondrial clearance that is initiated by PINK1 and Parkin.
authors.affiliation: Department of Life Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Shiori
authors.initials: S
authors.lastname: Akabane
authors.affiliation: Department of Life Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Midori
authors.initials: M
authors.lastname: Uno
authors.affiliation: Liaison Laboratory Research Promotion Center, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Tani
authors.affiliation: Department of Life Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Shunta
authors.initials: S
authors.lastname: Shimazaki
authors.affiliation: Department of Life Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.
authors.forename: Natsumi
authors.initials: N
authors.lastname: Ebara
authors.affiliation: Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kato
authors.affiliation: Division of Cell Signaling, Fujii Memorial Institute of Medical Sciences, Tokushima University, Tokushima 770-8503, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Kosako
authors.affiliation: Department of Life Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan. Electronic address: toka@rikkyo.ac.jp.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Oka
mesh_terms: D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology* / Q000648:ultrastructure; D051336:Mitochondrial Membranes / Q000201:enzymology / Q000648:ultrastructure; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D055550:Protein Stability; D021381:Protein Transport; D034622:RNA Interference; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D000099202:PTEN-Induced Putative Kinase
chemical_list: D017868:Cyclic AMP-Dependent Protein Kinases; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D009124:Muscle Proteins; D011494:Protein Kinases; D044767:Ubiquitin-Protein Ligases; D000099202:PTEN-Induced Putative Kinase; C521110:CHCHD3 protein, human; C088548:IMMT protein, human; C111567:parkin protein