Supernatants (soluble portion) were analyzed by Blue Native-polyacrylamide gel electrophoresis (BN-PAGE). However, -synuclein overexpression experienced no effect on Cu-induced oxidative stress. WT or A53T -synuclein overexpression exacerbated Cu toxicity in dopaminergic cells and candida in the absence of -synuclein aggregation. Cu improved autophagic flux and protein ubiquitination. Impairment of autophagy by overexpression of a dominant bad Atg5 form or inhibition of the ubiquitin/proteasome system (UPS) with MG132 enhanced Cu-induced cell death. However, only inhibition of the UPS stimulated the synergistic harmful effects of Cu and -synuclein overexpression. Our results demonstrate that -synuclein stimulates Cu toxicity in dopaminergic cells self-employed from its aggregation via modulation of protein degradation pathways. W303-1A WT strain (for 30 min at 4 C. The supernatant was collected and the pellet was discarded. The supernatant (comprising remaining soluble and detached peripheral membrane proteins) and cytosolic fractions were precipitated in TCA (final concentration of 25% [v/v]). The precipitates were washed twice with ice-cold acetone and resuspended in lysis buffer. Isolation of whole cell lysates, western-immunoblotting (WB) and SDS-PAGE of SK-N-SH were performed as explained previously (Rodriguez-Rocha et al., 2012). Blots were incubated with the related primary antibodies over night (1:1000): p-AMPK1 (Thr172, 2535), cleaved-caspase 3 (Asp 175, DNQX 9661), -synuclein (2642, carboxy-terminal sequence), ubiquitin (3936), and p-Ulk1 (Ser555, 5869) (Cell Signaling); AMPK1 (Ab32047), ATP7A (Ab42486), Nrf2 (Ab62352), and Ulk1 (Ab65050) (Abcam); LC3B (L7543, SIGMA); and Ctr1 (sc66847, Santa Cruz Biotechnology). Blots were reprobed with -actin (A2228, SIGMA) or GAPDH (2118, Cell Signaling) to verify equivalent protein loading. For analysis of -synuclein oligomers in soluble and insoluble fractions, cells were in the beginning lysed with 10 mM Tris/HCl pH 7.4, 105 mM NaCl, 3 mM MgCl2, 0.1% (v/v) Triton X-100 and Halt protease inhibitor cocktail containing buffer. Samples were centrifuged at 9,600 g. Supernatants (soluble portion) were analyzed by Blue Native-polyacrylamide gel electrophoresis (BN-PAGE). Pellets were lysed in RIPA buffer (0.1% [w/v] sodium dodecyl sulfate [SDS], 50 mM Tris-base, 150 mM NaCl, 1% [v/v] Triton X-100. 0.5% [w/v] sodium deoxycholate, pH 8.0) and components (insoluble fractions) were analyzed by NUPAGE/SDS-PAGE (Life Sciences/Invitrogen). Filter capture assay for ubiquitinated protein aggregates Cells were harvested in RIPA buffer. Samples were sonicated, centrifuged, and pellets discarded. DNQX Proteins were denatured in LDS-sample buffer (NUPAGE). 25C50 g of protein were filtered inside a nitrocellulose membrane previously equilibrated in NUPAGE transfer buffer using a dot blotter (Scie-Plas). Membrane was washed twice (2% [w/v] SDS, 10 mM Tris-EDTA, pH 7.5) and ubiquitin aggregates were detected by immunoblotting. Confocal microscopy Confocal microscopy of GFP-LC3-labeled autophagosomes and MitoTracker Deep Red-labeled mitochondria in SK-N-SH cells was performed as explained previously (Garcia-Garcia et al., 2013). For visualization of GFP-tagged -Synuclein in candida, pre-cultures of synchronized cells were cultivated in glycerol/lactate medium overnight and transferred into the medium comprising 2% [w/v] raffinose or 2% [w/v] galactose with or without CuCl2. Live cells and GFP were then visualized with Olympus IX81 inverted confocal laser scanning microscope (Olympus America) at 488 nm under oil immersion. Images were acquired using Fluoview 500 Software (Olympus America). Statistical analysis Experiment replicas were self-employed and performed on independent days. Collected data were analyzed by using one-way, two-way or three-way ANOVA, and the appropriate post-hoc test using SIGMA-PLOT/STAT package. When ANOVA assumptions were not met (normality or equivalent variance), Kruskal-Wallis ONE OF THE WAYS ANOVA on Ranks or data transformation (two-way ANOVA) were performed on collected data. Data were plotted as mean standard error of the mean (SE) using the Mouse monoclonal antibody to cIAP1. The protein encoded by this gene is a member of a family of proteins that inhibits apoptosis bybinding to tumor necrosis factor receptor-associated factors TRAF1 and TRAF2, probably byinterfering with activation of ICE-like proteases. This encoded protein inhibits apoptosis inducedby serum deprivation and menadione, a potent inducer of free radicals. Alternatively splicedtranscript variants encoding different isoforms have been found for this gene same statistical package for data analysis. Circulation cytometry plots and western blots offered display the results of representative experiments. Densitometry analyses of WB were performed in Image J (NIH). Results Copper induces caspase-dependent apoptosis, which is definitely modulated by Cu content material and transport CuCl2 treatment for 48 h induced death in dopaminergic neuroblastoma cells inside a dose-dependent manner (Figs. 1ACB). Cell death was recognized by the loss of plasma membrane integrity (PI uptake) and the depletion in intracellular GSH content material (mBCl) (Figs. 1ACB). Cell death was also evaluated by Calcein retention (Fig. 1C). CuCl2-induced cell death was significantly reduced in the presence of the irreversible pan-caspase inhibitor z-VAD-FMK (Figs. 1ACC). CuCl2 also induced the cleavage/activation of caspase 3 (Fig. 1D). However, inhibition of caspase 3 with Ac-DMQD-CHO experienced no effect on CuCl2 toxicity (Fig. 1C), which might be explained from the compensatory part of additional executioner caspases (Zheng et al., 2000). The difference between the level of sensitivity of PI uptake/GSH depletion (Figs. 1ACB) and Calcein retention assays DNQX (Fig. 1C), to detect the loss in cell viability induced byCuCl2, might be related to the fact that Calcein.