DJ-1 Null Dopaminergic Neuronal Cells Exhibit Defects in Mitochondrial Function and Structure: Involvement of Mitochondrial Complex I Assembly

Abstract

DJ-1 is a Parkinson's disease-associated gene whose protein product has a protective role in cellular homeostasis by removing cytosolic reactive oxygen species and maintaining mitochondrial function. However, it is not clear how DJ-1 regulates mitochondrial function and why mitochondrial dysfunction is induced by DJ-1 deficiency. In a previous study we showed that DJ-1 null dopaminergic neuronal cells exhibit defective mitochondrial respiratory chain complex I activity. In the present article we investigated the role of DJ-1 in complex I formation by using blue native-polyacrylamide gel electrophoresis and 2-dimensional gel analysis to assess native complex status. On the basis of these experiments, we concluded that DJ-1 null cells have a defect in the assembly of complex I. Concomitant with abnormal complex I formation, DJ-1 null cells show defective supercomplex formation. It is known that aberrant formation of the supercomplex impairs the flow of electrons through the channels between respiratory chain complexes, resulting in mitochondrial dysfunction. We took two approaches to study these mitochondrial defects. The first approach assessed the structural defect by using both confocal microscopy with MitoTracker staining and electron microscopy. The second approach assessed the functional defect by measuring ATP production, O2 consumption, and mitochondrial membrane potential. Finally, we showed that the assembly defect as well as the structural and functional abnormalities in DJ-1 null cells could be reversed by adenovirus-mediated overexpression of DJ-1, demonstrating the specificity of DJ-1 on these mitochondrial properties. These mitochondrial defects induced by DJ-1mutation may be a pathological mechanism for the degeneration of dopaminergic neurons in Parkinson's disease.

PARK7 protein translocating into spermatozoa mitochondria in Chinese asthenozoospermia

“…AS, asthenozoospermia; MiA, mild asthenozoospermia; MoA, moderate asthenozoospermia. addition, several observations have confirmed that PARK7 is translocated from the cytoplasm into the mitochondria when MMP is decreased (Ooe et al 2005, Junn et al 2009, Hao et al 2010, Krebiehl et al 2010, Heo et al 2012, Kaneko et al 2013, and it maintained the CI activity by directly binding to NDUFA4 and ND1, nuclear and mitochondrial DNAencoding subunits of the mitochondria respectively (Hayashi et al 2009). Along this line, we detected the location of PARK7 by staining the spermatozoa with an anti-DJ1 antibody.…”

Products of the Parkinson’s-disease related glyoxalase DJ-1, D-lactate and glycolate, support mitochondrial membrane potential and neuronal survival

“…DJ-1 is reported to exert its neuroprotective function in mitochondria (Junn et al, 2009). Many genes involved in Parkinson's disease, among them DJ-1, have been linked to alterations in mitochondrial structure and function and an enhanced sensitivity to mitochondrial toxins like Complex-I inhibitors (Clark et al, 2006;Park et al, 2006;Irrcher et al, 2010;Kamp et al, 2010;Sai et al, 2012;Wang et al, 2012;Burchell et al, 2013). Thus we decided to test the structure and function of mitochondria in the absence of DJ-1 (ΔΔdjr) or complete glyoxalase activity (Δglo), as revealed by staining with MitoTracker CMXRos (Figure 2A) (Pendergrass et al, 2004).…”

“…One of such genes is DJ-1/PARK7, which was originally reported as an oncogene (Nagakubo et al, 1997), and associated with familial Parkinson's disease (Bonifati et al, 2003). DJ-1 deficiency was reported to lead to abnormal mitochondrial morphology and dynamics, increased sensitivity to oxidative stress, decreased mitochondrial membrane potential, and opening of the mitochondrial permeability transition pore (Irrcher et al, 2010;Giaime et al, 2012). DJ-1 protein exerts its neuroprotective function against oxidative stress primarily in mitochondria (Junn et al, 2009).…”

Common Mechanisms of Onset of Cancer and Neurodegenerative Diseases

“…48,64,145) Mitochondria with abnormal morphology such as fragmented mitochondria and with reduced mitochondrial membrane potential are observed in DJ-1-knockout mice. 142,143) We have found that DJ-1 binds to subunits of mitochondrial complex I in respiration complexes, enhances its activity, and is co-localized with mitochondrial complex I in the mitochondrial inner membrane. 48) Furthermore, the N-terminal 12 amino acids are necessary for DJ-1 to localize to mitochondria, and pathogenic mutants of DJ-1 such as L166P and M26I DJ-1 are localized in mitochondria as monomers.…”

“…DJ-1 is a multi-functional protein, [118][119][120] having functions in transcriptional regulation, [121][122][123][124][125][126][127][128][129][130][131][132][133][134][135] anti-oxidative stress reaction, 64,112,113,136,137) mitochondrial regulation, 48,[138][139][140][141][142][143][144][145][146] regulation of signal transduction, 96,123,132,[147][148][149][150][151][152] and functions as a protease, 58,[153][154][155] a chaperone 156,157) and a deglycase 158) (Fig. 5).…”