Characterization of PINK1 (PTEN-induced putative kinase 1) mutations associated with Parkinson disease in mammalian cells and Drosophila
ABSTRACT Mutations in PTEN-induced putative kinase 1 (PINK1) are tightly linked to autosomal recessive Parkinson's disease (PD). Although more than 50 mutations in PINK1 have been discovered, the role of these mutations in PD pathogenesis remains poorly understood. Here, we characterized 17 representative PINK1 pathogenic mutations in both mammalian cells and Drosophila. These mutations did not affect the typical cleavage patterns and subcellular localization of PINK1 under both normal and damaged-mitochondria conditions in mammalian cells. However, PINK1 mutations in the kinase domain failed to translocate Parkin to mitochondria and to induce mitochondrial aggregation. Consistent with the mammalian data, Drosophila PINK1 mutants with mutations in the kinase domain (G426D and L464P) did not genetically interact with Parkin. Furthermore, PINK1-null flies expressing the transgenic G426D mutant displayed defective phenotypes with increasing age, whereas L464P mutant-expressing flies exhibited the phenotypes at an earlier age. Collectively, these results strongly support the hypothesis that the kinase activity of PINK1 is essential for its function and for regulating downstream Parkin functions in mitochondria. We believe that this study provides the basis for understanding the molecular and physiological functions of various PINK1 mutations and provides insights into the pathogenic mechanisms of PINK1-linked PD.
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- "In healthy mitochondria, PINK1 translocates to the IMM via the TOMM20 machinery, where it is cleaved and rapidly degraded by the mitochondrial inner membrane rhomboid protease presenilinassociated rhomboid-like protease (Jin et al., 2010; Meissner et al., 2011) as well as other mitochondrial proteases MMP, m-AAA and ClpXP (Van Laar & Berman, 2013). In damaged mitochondria, when the membrane potential is lowered, mitochondrial import of PINK1 by the TOMM machinery is inhibited, resulting in accumulation of full-length PINK1 on the OMM (Corti & Brice, 2013) where it plays a pivotal role in the removal of damaged mitochondria from the cell (Becker et al., 2012; Song et al., 2013). "
ABSTRACT: Parkinson's disease (PD) is characterised by the loss of dopaminergic neurons in the midbrain. Autosomal recessive, early-onset cases of PD are predominantly caused by mutations in the parkin, PINK1 and DJ-1 genes. Animal and cellular models have verified a direct link between parkin and PINK1, whereby PINK1 phosphorylates and activates parkin at the outer mitochondrial membrane, resulting in removal of dysfunctional mitochondria via mitophagy. Despite the overwhelming evidence for this interaction, few studies have been able to identify a link for DJ-1 with parkin or PINK1. The aim of this review is to summarise the functions of these three proteins, and to analyse the existing evidence for direct and indirect interactions between them. DJ-1 is able to rescue the phenotype of PINK1-knockout Drosophila models, but not of parkin-knockouts, suggesting that DJ-1 may act in a parallel pathway to that of the PINK1/parkin pathway. To further elucidate a commonality between these three proteins, bioinformatics analysis established that Miro (RHOT1) interacts with parkin and PINK1, and HSPA4 interacts with all three proteins. Furthermore, 30 transcription factors were found to be common amongst all three proteins, with many of them being involved in transcriptional regulation. Interestingly, expression of these proteins and their associated transcription factors are found to be significantly down-regulated in PD patients compared to healthy controls. In summary, this review provides insight into common pathways linking three PD-causing genes and highlights some key questions, the answers to which may provide critical insight into the disease process. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.European Journal of Neuroscience 03/2015; 41(9). DOI:10.1111/ejn.12872 · 3.67 Impact Factor
- "Uch No No No Yes (Thao et al., 2012; Tram et al., 2013) PARK6 PINK1 Pink1 Yes (Clark et al., 2006; Park et al., 2006) Yes (Clark et al., 2006; Kim et al., 2008; Park et al., 2006; Todd and Staveley, 2008; Yang et al., 2006) Yes (G309D⁎ (Wang et al., 2006), G426D⁎ (genomic construct) (Yun et al., 2008), G426D⁎–L464P⁎ (Song et al., 2013) Yes (Park et al., 2006; Yang et al., 2006) "
Article: Flies with Parkinson’s Disease[Show abstract] [Hide abstract]
ABSTRACT: Parkinson's disease is an incurable neurodegenerative disease. Most cases of the disease are of sporadic origin, but about 10% of the cases are familial. The genes thus far identified in Parkinson's disease are well conserved. Drosophila is ideally suited to study the molecular neuronal cell biology of these genes and the pathogenic mutations in Parkinson's disease. Flies reproduce fast and their elaborate and modern genetic tools in combination with their small size allows researchers to analyze identified cells and neurons in large numbers of animals. Furthermore, fruit flies recapitulate many of the organellar and molecular defects also seen in patients, and these defects often result in clear phenotypes also at the level of locomotion and behavior, facilitating genetic modifier screens. Hence, Drosophila has played a prominent role in Parkinson's disease research and has provided invaluable insight into the molecular mechanisms of this disease. Copyright © 2015. Published by Elsevier Inc.Experimental Neurology 02/2015; DOI:10.1016/j.expneurol.2015.02.020 · 4.62 Impact Factor
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- "Similarly, the other novel point deletion in exon 7: c.1423delC; p.A443AfsX481 created a stop codon 38 amino acids downstream from the frameshift at position 481 in the deduced protein, giving rise to a protein of 481 aminoacids and thereby disrupting the kinase domain (Fig. 1B). Mutations in the transmembranal region fail to localize parkin to mitochondria [Song et al., 2013] and several mitochondrial protease cleavage sites reside in the segment containing the first 156 residues of PINK1 [Sim et al., 2012]. The p.G91GfsX105 change may disturb the mitochondrial translocation of PINK1, but further functional analyzes are required to confirm this hypothesis. "
ABSTRACT: Mutations in PARK2, PINK1, and DJ-1 have been associated with autosomal recessive early-onset Parkinson's disease. Here, we report the prevalence of sequence and structural mutations in these three main recessive genes in Mexican Mestizo patients. The complete sequences of these three genes were analyzed by homo/heteroduplex DNA formation and direct sequencing; exon dosage was determined by multiplex ligation-dependent probe amplification and real-time PCR in 127 patients belonging to 122 families and 120 healthy Mexican Mestizo controls. All individuals had been previously screened for the three most common LRRK2 mutations. The presence of two mutations in compound heterozygous or homozygous genotypes was found in 16 unrelated patients, 10 had mutations in PARK2, six in PINK1, and none in DJ-1. Two PARK2-PINK1 and one PARK2-LRRK2 digenic cases were observed. Novel mutations were identified in PARK2 and PINK1 genes, including PINK1 duplication for the first time. Exon dosage deletions were the most frequent mutations in PARK2 (mainly in exons 9 and 12), followed by those in PINK1. The high prevalence of heterozygous mutations in PARK2 (12.3%) and the novel heterozygous and homozygous point mutations in PINK1 observed in familial and sporadic cases from various states of Mexico support the concept that single heterozygous mutations in recessive Parkinson's disease genes play a pathogenic role. These data have important implications for genetic counseling of Mexican Mestizo patients with early-onset Parkinson's disease. The presence of digenic inheritance underscores the importance of studying several genes in this disease. A step-ordered strategy for molecular diagnosis is proposed. © 2014 Wiley Periodicals, Inc.American Journal of Medical Genetics Part B Neuropsychiatric Genetics 04/2014; 165(3). DOI:10.1002/ajmg.b.32228 · 3.27 Impact Factor