Compelling evidence indicates that two autosomal recessive Parkinson's disease genes, PINK1 (PARK6) and Parkin (PARK2), cooperate to mediate the autophagic clearance of damaged mitochondria (mitophagy). Mutations in the F-box domain–containing protein Fbxo7 (encoded by PARK15) also cause early-onset autosomal recessive Parkinson's disease, by an unknown mechanism. Here we show that Fbxo7 participates in mitochondrial maintenance through direct interaction with PINK1 and Parkin and acts in Parkin-mediated mitophagy. Cells with reduced Fbxo7 expression showed deficiencies in translocation of Parkin to mitochondria, ubiquitination of mitofusin 1 and mitophagy. In Drosophila, ectopic overexpression of Fbxo7 rescued loss of Parkin, supporting a functional relationship between the two proteins. Parkinson's disease–causing mutations in Fbxo7 interfered with this process, emphasizing the importance of mitochondrial dysfunction in Parkinson's disease pathogenesis.
At a glance
- Parkin is recruited selectively to impaired mitochondria and promotes their autophagy. J. Cell Biol. 183, 795–803 (2008). , , &
- PINK1-dependent recruitment of Parkin to mitochondria in mitophagy. Proc. Natl. Acad. Sci. USA 107, 378–383 (2010). et al.
- PINK1 is selectively stabilized on impaired mitochondria to activate Parkin. PLoS Biol. 8, e1000298 (2010). et al.
- PINK1/Parkin-mediated mitophagy is dependent on VDAC1 and p62/SQSTM1. Nat. Cell Biol. 12, 119–131 (2010). et al.
- Mitophagy and Parkinson's disease: the PINK1-parkin link. Biochim. Biophys. Acta 1813, 623–633 (2011). , &
- Mitochondrial membrane potential regulates PINK1 import and proteolytic destabilization by PARL. J. Cell Biol. 191, 933–942 (2010). et al.
- Rhomboid-7 and HtrA2/Omi act in a common pathway with the Parkinson's disease factors Pink1 and Parkin. Dis. Model. Mech. 1, 168–174 discussion 173 (2008). et al.
- Drosophila parkin requires PINK1 for mitochondrial translocation and ubiquitinates mitofusin. Proc. Natl. Acad. Sci. USA 107, 5018–5023 (2010). , &
- The mitochondrial fusion-promoting factor mitofusin is a substrate of the PINK1/parkin pathway. PLoS ONE 5, e10054 (2010). , , , &
- Mitofusin 1 and mitofusin 2 are ubiquitinated in a PINK1/parkin-dependent manner upon induction of mitophagy. Hum. Mol. Genet. 19, 4861–4870 (2010). et al.
- Parkin-mediated selective mitochondrial autophagy, mitophagy: Parkin purges damaged organelles from the vital mitochondrial network. FEBS Lett. 584, 1386–1392 (2010).
- Mutations in PINK1 and Parkin impair ubiquitination of Mitofusins in human fibroblasts. PLoS ONE 6, e16746 (2011). et al.
- Landscape of the PARKIN-dependent ubiquitylome in response to mitochondrial depolarization. Nature 496, 372–376 (2013). et al.
- Proteasome and p97 mediate mitophagy and degradation of mitofusins induced by Parkin. J. Cell Biol. 191, 1367–1380 (2010). et al.
- Genome-wide linkage analysis of a Parkinsonian-pyramidal syndrome pedigree by 500 K SNP arrays. Am. J. Hum. Genet. 82, 1375–1384 (2008). et al.
- FBXO7 mutations cause autosomal recessive, early-onset parkinsonian-pyramidal syndrome. Neurology 72, 240–245 (2009). et al.
- Early-onset L-dopa-responsive parkinsonism with pyramidal signs due to ATP13A2, PLA2G6, FBXO7 and spatacsin mutations. Mov. Disord. 25, 1791–1800 (2010). et al.
- F-box proteins are receptors that recruit phosphorylated substrates to the SCF ubiquitin-ligase complex. Cell 91, 209–219 (1997). , , , &
- Fbx7 functions in the SCF complex regulating Cdk1-cyclin B-phosphorylated hepatoma up-regulated protein (HURP) proteolysis by a proline-rich region. J. Biol. Chem. 279, 32592–32602 (2004). , , &
- Transforming activity of Fbxo7 is mediated specifically through regulation of cyclin D/cdk6. EMBO J. 24, 3104–3116 (2005). et al.
- Identification of F-box only protein 7 as a negative regulator of NF-κB signalling. J. Cell Mol. Med. 16, 2140–2149 (2012). et al.
- Structure of a conserved dimerization domain within the F-box protein Fbxo7 and the PI31 proteasome inhibitor. J. Biol. Chem. 283, 22325–22335 (2008). et al.
- The F-box protein Fbxo7 interacts with human inhibitor of apoptosis protein cIAP1 and promotes cIAP1 ubiquitination. Biochem. Biophys. Res. Commun. 342, 1022–1026 (2006). , , , &
- Mitochondrial pathology and apoptotic muscle degeneration in Drosophila parkin mutants. Proc. Natl. Acad. Sci. USA 100, 4078–4083 (2003). et al.
- Increased glutathione S-transferase activity rescues dopaminergic neuron loss in a Drosophila model of Parkinson's disease. Proc. Natl. Acad. Sci. USA 102, 8024–8029 (2005). et al.
- Mitochondrial dysfunction in Drosophila PINK1 mutants is complemented by parkin. Nature 441, 1157–1161 (2006). et al.
- Drosophila pink1 is required for mitochondrial function and interacts genetically with parkin. Nature 441, 1162–1166 (2006). et al.
- A conserved F box regulatory complex controls proteasome activity in Drosophila. Cell 145, 371–382 (2011). et al.
- A novel F-box protein is required for caspase activation during cellular remodeling in Drosophila. Development 137, 1679–1688 (2010). , &
- Mitochondrial pathology and muscle and dopaminergic neuron degeneration caused by inactivation of Drosophila Pink1 is rescued by Parkin. Proc. Natl. Acad. Sci. USA 103, 10793–10798 (2006). et al.
- Loss-of-function of human PINK1 results in mitochondrial pathology and can be rescued by parkin. J. Neurosci. 27, 12413–12418 (2007). et al.
- Characterization of PINK1 (PTEN-induced Putative Kinase 1) mutations associated with Parkinson disease in mammalian cells and Drosophila. J. Biol. Chem. 288, 5660–5672 (2013). et al.
- Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes. Autophagy 4, 151–175 (2008). et al.
- Nix is critical to two distinct phases of mitophagy, reactive oxygen species-mediated autophagy induction and Parkin-ubiquitin-p62-mediated mitochondrial priming. J. Biol. Chem. 285, 27879–27890 (2010). et al.
- A functional role for the p62–ERK1 axis in the control of energy homeostasis and adipogenesis. EMBO Rep. 11, 226–232 (2010). et al.
- Guidelines for the use and interpretation of assays for monitoring autophagy. Autophagy 8, 445–544 (2012). et al.
- A competitive binding mechanism between SKP1 and exportin 1 (CRM1) controls the localization of a subset of F-box proteins. J. Biol. Chem. 286, 19804–19815 (2011). &
- PINK1 is activated by mitochondrial membrane potential depolarization and stimulates Parkin E3 ligase activity by phosphorylating serine 65. Open Biol. 2, 120080 (2012). et al.
- A knowledge base for predicting protein localization sites in eukaryotic cells. Genomics 14, 897–911 (1992). &
- Computational method to predict mitochondrially imported proteins and their targeting sequences. Eur. J. Biochem. 241, 779–786 (1996). &
- Predotar: a tool for rapidly screening proteomes for N-terminal targeting sequences. Proteomics 4, 1581–1590 (2004). , , &
- Probing tumor phenotypes using stable and regulated synthetic microRNA precursors. Nat. Genet. 37, 1289–1295 (2005). et al.
- Inhibition of proteasomal activity causes inclusion formation in neuronal and non-neuronal cells overexpressing Parkin. Mol. Biol. Cell 14, 4541–4556 (2003). et al.
- The mitochondrial protease HtrA2 is regulated by Parkinson's disease–associated kinase PINK1. Nat. Cell Biol. 9, 1243–1252 (2007). et al.
- Presence of a pre-apoptotic complex of pro-caspase-3, Hsp60 and Hsp10 in the mitochondrial fraction of Jurkat cells. EMBO J. 18, 2040–2048 (1999). , , , &
- Drosophila HtrA2 is dispensable for apoptosis but acts downstream of PINK1 independently from Parkin. Cell Death Differ. 16, 1118–1125 (2009). et al.
- Drosophila Protocols Ch.13, 240–241 (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, USA, 2000). , &
- Supplementary Text and Figures (10,178 KB)
Supplementary Figures 1–9