title: Quantitative Profiling for Substrates of the Mitochondrial Presequence Processing Protease Reveals a Set of Nonsubstrate Proteins Increased upon Proteotoxic Stress.
abstract: The majority of mitochondrial preproteins are targeted via N-terminal presequences that are cleaved upon import into the organelle. The essential mitochondrial processing protease (MPP) is assumed to cleave the majority of incoming precursors; however, only a small fraction of mitochondrial precursors have been experimentally analyzed limiting the information on MPP recognition and substrate specificity. Here we present the first systematic approach for identification of authentic MPP substrate proteins using a temperature-sensitive mutant of the MPP subunit Mas1. Inactivation of MPP at nonpermissive temperature leads to accumulation of immature precursors in mitochondria, which were measured by quantitative N-terminal ChaFRADIC. This led to the identification of 66 novel MPP substrates. Deduction of the cleaved presequences determines arginine in position -2 of the cleavage site as a main factor for MPP recognition. Interestingly, a set of nonprocessed proteins was also increased in mas1 mutant mitochondria. Additionally, mas1 mitochondria respond to temperature elevation with an increase in membrane potential and oxygen consumption. These changes might indicate that mas1 cells exert a response to balance the proteotoxic stress induced by MPP dysfunction.
authors.affiliation: Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V. , Otto-Hahn-Str. 6b, 44227 Dortmund, Germany.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Burkhart
authors.affiliation: Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg , Stefan-Meier-Str. 17, 79104 Freiburg, Germany.|Faculty of Biology, Universität Freiburg , Schänzlestrasse 1, 79104 Freiburg, Germany.|Spemann Graduate School of Biology and Medicine, University of Freiburg , Albertstrasse 19A, 79104 Freiburg, Germany.
authors.forename: Asli A
authors.initials: AA
authors.lastname: Taskin
authors.affiliation: Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V. , Otto-Hahn-Str. 6b, 44227 Dortmund, Germany.
authors.forename: René P
authors.initials: RP
authors.lastname: Zahedi
authors.affiliation: Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg , Stefan-Meier-Str. 17, 79104 Freiburg, Germany.
authors.forename: F-Nora
authors.initials: FN
authors.lastname: Vögtle
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000595:Amino Acid Sequence; D001120:Arginine / Q000378:metabolism; D001665:Binding Sites; D002845:Chromatography / Q000295:instrumentation / Q000379:methods; D015966:Gene Expression Regulation, Fungal; D006358:Hot Temperature; D053078:Membrane Potential, Mitochondrial / Q000502:physiology; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D009154:Mutation; D010101:Oxygen Consumption; D011485:Protein Binding; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics; D013379:Substrate Specificity; D000096122:Mitochondrial Processing Peptidase
chemical_list: D001120:Arginine; D008666:Metalloendopeptidases; D011498:Protein Precursors; D021122:Protein Subunits; D000096122:Mitochondrial Processing Peptidase
keywords: ChaFRADIC; mitochondria; mitochondrial processing protease; mitochondrial stress response; presequence protein import; protein turnover; proteostasis