Reduced Basal Autophagy and Impaired Mitochondrial Dynamics Due to Loss of Parkinson’s Disease-Associated Protein DJ-1 Guido Krebiehl1, Sabine Ruckerbauer2, Lena F. Burbulla1,3, Nicole Kieper1, Brigitte Maurer1, Jens Waak1¤, Hartwig Wolburg4, Zemfira Gizatullina5, Frank N. Gellerich6, Dirk Woitalla7, Olaf Riess8, Philipp J. Kahle1, Tassula Proikas-Cezanne2*, Rejko Kru¨ ger1* 1 Center of Neurology and Hertie-Institute for Clinical Brain Research, University of Tu¨ bingen, Tu¨ bingen, Germany, 2 Autophagy Laboratory, Interfaculty Institute for Cell Biology, University of Tu¨ bingen, Tu¨ bingen, Germany, 3 Graduate School of Cellular and Molecular Neuroscience, University of Tuebingen, Tu¨ bingen, Germany, 4 Institute of Pathology, University of Tu¨ bingen, Tu¨ bingen, Germany, 5 Department of Neurology, Otto von Guericke University of Magdeburg, Magdeburg, Germany, 6 KeyNeurotek Pharmaceuticals AG, ZENIT, Magdeburg, Germany, 7 Department of Neurology, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany, 8 Department of Medical Genetics, University of Tu¨ bingen, Tu¨ bingen, Germany Abstract Background: Mitochondrial dysfunction and degradation takes a central role in current paradigms of neurodegeneration in Parkinson’s disease (PD). Loss of DJ-1 function is a rare cause of familial PD. Although a critical role of DJ-1 in oxidative stress response and mitochondrial function has been recognized, the effects on mitochondrial dynamics and downstream consequences remain to be determined. Methodology/Principal Findings: Using DJ-1 loss of function cellular models from knockout (KO) mice and human carriers of the E64D mutation in the DJ-1 gene we define a novel role of DJ-1 in the integrity of both cellular organelles, mitochondria and lysosomes. We show that loss of DJ-1 caused impaired mitochondrial respiration, increased intramitochondrial reactive oxygen species, reduced mitochondrial membrane potential and characteristic alterations of mitochondrial shape as shown by quantitative morphology. Importantly, ultrastructural imaging and subsequent detailed lysosomal activity analyses revealed reduced basal autophagic degradation and the accumulation of defective mitochondria in DJ-1 KO cells, that was linked with decreased levels of phospho-activated ERK2. Conclusions/Significance: We show that loss of DJ-1 leads to impaired autophagy and accumulation of dysfunctional mitochondria that under physiological conditions would be compensated via lysosomal clearance. Our study provides evidence for a critical role of DJ-1 in mitochondrial homeostasis by connecting basal autophagy and mitochondrial integrity in Parkinson’s disease. Citation: Krebiehl G, Ruckerbauer S, Burbulla LF, Kieper N, Maurer B, et al. (2010) Reduced Basal Autophagy and Impaired Mitochondrial Dynamics Due to Loss of Parkinson’s Disease-Associated Protein DJ-1. PLoS ONE 5(2): e9367. doi:10.1371/journal.pone.0009367 Editor: Leonard Petrucelli, Mayo Clinic, United States of America Received September 16, 2009; Accepted January 27, 2010; Published February 23, 2010 Copyright: 2010 Krebiehl et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was supported by grants from the German Research Council [DFG, KR2119/3-1]; the Federal Ministry for Education and Research [BMBF, NGFNplus; 01GS08134]; and the Faculty of Medicine, University of Tubingen [Fortuene 1709-0-0] to RK; and grants of the Federal Ministry for Education and Research [BMBF, BioProfile]; Landesstiftung Baden Wuerttemberg; and the German Research Council [SFB773] to TPC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: One of the authors is employed by a commercial company, (i.e. KeyNeurotek Pharmaceuticals). This company therefore may formally act as a funder due to employment of one authors of this study. However, this funder did not play any role in this study, since only the expertise of FNG in terms of respirometry Figure 1 independently from his affiliation was subject of cooperation. Therefore no financial disclosure or specification of the role of the funder needs to be declared. * E-mail: tassula.proikas-cezanne@uni-tuebingen.de (TP-C); rejko.krueger@uni-tuebingen.de (RK) ¤ Current address: Nexigen GmbH, Bonn, Germany Introduction The identification of genetic causes of Parkinson’s disease (PD) only ten years ago allowed first insights into the molecular mechanisms leading to neurodegeneration in this common movement disorder. These mechanisms include the pathological misfolding of disease-related proteins, disturbed ubiquitin-mediat- ed protein degradation pathways and the accumulation of intraneuronal protein aggregates in affected brain areas, also known as Lewy bodies [1]. The identification of PD-specific mutations in nuclear genes encoding mitochondrial proteins provided the first genetic link to the variety of biochemical findings implicating a disturbed mitochondrial function in PD pathogenesis [2,3,4]. Mutations in the DJ-1 gene were identified as a rare cause of autosomal-recessive PD [5] and account for approximately 1–2% of all early-onset forms of PD [6]. To date, several homozygous deletions and point mutations in the DJ-1 gene encoding a highly conserved 189 amino acid protein are known to cause PD due to a loss of protein function [5,7,8]. The physiological role of DJ-1 PLoS ONE | www.plosone.org 1 February 2010 | Volume 5 | Issue 2 | e9367