Authors: Benjamin Dehay, Marta Martinez-Vicente, Alfredo Ramirez, Celine Perier, Christine Klein, Miquel Vila and Erwan Bezard

Benjamin Dehay

Corresponding author: benjamin.dehay@u-bordeaux2.fr
Institut des Maladies Neurodégénératives; Université de Bordeaux; CNRS UMR 5293; Bordeaux, France

Marta Martinez-Vicente

Neurodegenerative Diseases Research Group; Vall d’Hebron Research Institute–CIBERNED; Barcelona, Spain

Alfredo Ramirez

Section of Clinical and Molecular Neurogenetics; Department of Neurology; University of Lübeck; Lübeck, Germany; Department of Psychiatry and Psychotherapy; University of Bonn; Bonn, Germany

Celine Perier

Neurodegenerative Diseases Research Group; Vall d’Hebron Research Institute–CIBERNED; Barcelona, Spain

Christine Klein

Section of Clinical and Molecular Neurogenetics; Department of Neurology; University of Lübeck; Lübeck, Germany

Miquel Vila

Neurodegenerative Diseases Research Group; Vall d’Hebron Research Institute–CIBERNED; Barcelona, Spain; Department of Biochemistry and Molecular Biology; Autonomous University of Barcelona (UAB); Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA); Barcelona, Spain

Erwan Bezard

Institut des Maladies Neurodégénératives; Université de Bordeaux; CNRS UMR 5293; Bordeaux, France

Abstract:
Mutations in ATP13A2 (PARK9) cause an autosomal recessive form of early-onset parkinsonism with pyramidal degeneration and dementia called Kufor-Rakeb Syndrome (KRS). The ATP13A2 gene encodes a transmembrane lysosomal P5-type ATPase (ATP13A2) whose physiological function in mammalian cells, and hence its potential role in Parkinson disease (PD), remains elusive. In this context, we have recently shown that KRS-linked mutations in ATP13A2 leads to several lysosomal alterations in ATP13A2 KRS patient-derived fibroblasts, including impaired lysosomal acidification, decreased proteolytic processing of lysosomal enzymes, reduced degradation of lysosomal substrates and diminished lysosomal-mediated clearance of autophagosomes (AP). Similar alterations are observed in stable ATP13A2-knockdown dopaminergic cell lines, which are associated with cell death. Restoration of ATP13A2 levels in ATP13A2-mutant/depleted cells is able to restore lysosomal function and attenuate cell death. Relevant to PD, we have determined that ATP13A2 levels are decreased in dopaminergic nigral neurons from sporadic PD patients. Interestingly in these patients, the main signal of ATP13A2 is detected in the Lewy bodies. Our results unravel an instrumental role of ATP13A2 in lysosomal function and in cell viability. Altogether, our results validate ATP13A2 as a likely therapeutic target against PD degeneration.

Autophagic Punctum to:
B Dehay, A Ramirez, M Martinez-Vicente, C Perier, MH Canron, E Doudnikoff, et al. Loss of P-type ATPase ATP13A2/PARK9 function induces general lysosomal deficiency and leads to Parkinson disease neurodegeneration. Proc Natl Acad Sci U S A 2012; 125: 3170-81
PMID: 22647602 DOI: 10.1073/pnas.1112368109

Received: June 4, 2012; Accepted: June 5, 2012; Published Online: August 13, 2012

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