Poly-ADP-ribose assisted protein localization resolves that DJ-1, but not LRRK2 or α-synuclein, is localized to the mitochondrial matrix.

Nelson Osuagwu,Christian Dölle,Charalampos Tzoulis

doi:10.1371/journal.pone.0219909

Nelson Osuagwu, Christian Dölle + Show 1 more

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https://doi.org/10.1371/journal.pone.0219909

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Journal: PloS one	Publication Date: Jul 19, 2019
Citations: 6	License type: CC BY 4.0

Affiliation: Haukeland University Hospital, University of Bergen

Abstract

Several proteins linked to familial Parkinson disease have been associated with mitochondrial (dys-)function and have been described to reside within mitochondria. The putative mitochondrial and sub-mitochondrial localization of these proteins remains disputed, however, potentially due to conflicting results obtained by diverging technical approaches. Using the high-resolution poly-ADP-ribose assisted protein localization assay that also allows for detection of low level and even partial mitochondrial matrix localization, we demonstrate here that DJ-1, but not LRRK2 or α-synuclein, resides in the mitochondrial matrix. The localization of the proteins was not changed in cellular stress models of Parkinson disease and, in case of α-synuclein, not affected by pathological mutations.Our results verify the ability of DJ-1 to carry out its role also from within mitochondria and suggest that LRRK2 and α-synuclein may interact with and affect mitochondria from outside the mitochondrial matrix.

Highlights

Parkinson disease (PD) is a complex disorder influenced by both genetic and environmental factors [1,2,3,4]
The open reading frame (ORF) encoding full-length DJ-1 was amplified from HEK293 cells cDNA, while the ORFs encoding the N-terminal domain of Leucine-rich repeat kinase 2 (LRRK2) and full-length α-synuclein were amplified from pre-existing plasmids (Addgene: pDEST53LRRK2-WT #25044 and EGFP-alpha synuclein-WT #40822, respectively)
When cells were subjected to PAR immunocytochemistry, cells overexpressing the DJ-1-PARP1cd fusion protein showed a positive PAR signal that did not colocalize with the diffuse, cytosolic pattern of the detected protein (Fig 2B, S1B Fig), but colocalized with mitochondria (S2 Fig)

Summary

Introduction

Parkinson disease (PD) is a complex disorder influenced by both genetic and environmental factors [1,2,3,4]. While disease mechanisms still remain largely unclear, it is well established that mitochondrial dysfunction plays a central role in both familial and sporadic PD [6]. This includes, among others, changes in mitochondrial quality control pathways such as mitochondrial DNA homeostasis and mitophagy [7,8], as well as metabolic changes such as complex I deficiency of the mitochondrial respiratory chain [9,10]. Several proteins that have been genetically linked to PD are involved in mitochondrial homeostasis and quality control, including PTEN-induced kinase 1 (PINK1), Parkin, DJ-1 and Leucine-rich repeat kinase 2 (LRRK2) [11,12,13].

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