Parkinson's disease is a debilitating movement disorder characterized by death of dopaminergic midbrain neurons. Mutations in PTEN-induced putative kinase 1 (PINK1) have been recently identified in familial parkinsonism, and some populations of early onset sporadic Parkinson's disease. In order to assess potential causative effects of mutations, it is necessary to first understand the regulation and function of wild type PINK1. One key unresolved issue is whether PINK1 is a functional kinase. This proposal is designed to investigate the feasibility of a novel research direction focused upon the regulation of PINK1 phosphorylation, localization, and function under conditions of stress elicited by parkinsonian neurotoxins. Our previous studies suggest that mitochondrially targeted kinase pathways play a central role in toxin-induced dopaminergic cell death. Thus, we hypothesize that PINK1 is a functional kinase that interacts with a set of cell death- regulatory kinases that localize to mitochondria. To address this hypothesis, we will determine if PINK1 shows kinase activity that is regulated by and participates in known mitochondrially targeted signaling pathways, using both cell free and culture systems. We will determine whether subcellular localization of PINK1 is regulated in neurotoxin models of dopaminergic cell death, and compare the effects of PINK1 and a kinase dead PINK1 mutant on mitochondrial cell death in dopaminergic cell lines and primary midbrain cultures. Completion of these studies will lead to a better understanding of the role of PINK1 during dopaminergic neuronal cell injury, and how it participates in signaling networks that influence whether these cells live or die. Following this exploratory/developmental phase, more extensive studies will be aimed at identifying downstream targets of PINK1 activation and the effects of disease-associated mutations on PINK1 regulation, as these may lead to novel therapeutic approaches. In addition, a group of immunochemical and molecular reagents will have been created that can facilitate the work of other investigators studying mechanisms of Parkinson's and related diseases. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21NS053777-02
Application #
7345641
Study Section
Special Emphasis Panel (ZRG1-NDBG (09))
Program Officer
Sutherland, Margaret L
Project Start
2006-03-01
Project End
2009-02-28
Budget Start
2007-03-01
Budget End
2009-02-28
Support Year
2
Fiscal Year
2007
Total Cost
$194,555
Indirect Cost
Name
University of Pittsburgh
Department
Pathology
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Chu, Charleen T (2010) Tickled PINK1: mitochondrial homeostasis and autophagy in recessive Parkinsonism. Biochim Biophys Acta 1802:20-8
Dagda, Ruben K; Cherra 3rd, Salvatore J; Kulich, Scott M et al. (2009) Loss of PINK1 function promotes mitophagy through effects on oxidative stress and mitochondrial fission. J Biol Chem 284:13843-55
Chu, Charleen T; Plowey, Edward D; Dagda, Ruben K et al. (2009) Autophagy in neurite injury and neurodegeneration: in vitro and in vivo models. Methods Enzymol 453:217-49
Cherra 3rd, Salvatore J; Dagda, Ruben K; Tandon, Anurag et al. (2009) Mitochondrial autophagy as a compensatory response to PINK1 deficiency. Autophagy 5:1213-4
Dagda, Ruben K; Zhu, Jianhui; Chu, Charleen T (2009) Mitochondrial kinases in Parkinson's disease: converging insights from neurotoxin and genetic models. Mitochondrion 9:289-98
Chu, Charleen T (2008) Eaten alive: autophagy and neuronal cell death after hypoxia-ischemia. Am J Pathol 172:284-7
Cherra, Salvatore J; Chu, Charleen T (2008) Autophagy in neuroprotection and neurodegeneration: A question of balance. Future Neurol 3:309-323
Kiselyov, Kirill; Jennigs Jr, John J; Rbaibi, Youssef et al. (2007) Autophagy, mitochondria and cell death in lysosomal storage diseases. Autophagy 3:259-62
Kulich, Scott M; Horbinski, Craig; Patel, Manisha et al. (2007) 6-Hydroxydopamine induces mitochondrial ERK activation. Free Radic Biol Med 43:372-83
Chu, Charleen T; Plowey, Edward D; Wang, Ying et al. (2007) Location, location, location: altered transcription factor trafficking in neurodegeneration. J Neuropathol Exp Neurol 66:873-83

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