Related Experiment Video
Updated: Aug 16, 2025
Assay Development for High Content Quantification of Sod1 Mutant Protein Aggregate Formation in Living Cells
Published on: October 4, 2017
Specific Post-Translational Modifications of VDAC3 in ALS-SOD1 Model Cells Identified by High-Resolution Mass
Maria Gaetana Giovanna Pittalà1, Simona Reina2, Stefano Conti Nibali2
1Organic Mass Spectrometry Laboratory, Department of Chemical Sciences, University of Catania, Via S. Sofia 64, 95123 Catania, Italy.
Abstract:
Damage induced by oxidative stress is a key driver of the selective motor neuron death in amyotrophic lateral sclerosis (ALS). Mitochondria are among the main producers of ROS, but they also suffer particularly from their harmful effects. Voltage-dependent anion-selective channels (VDACs) are the most represented proteins of the outer mitochondrial membrane where they form pores controlling the permeation of metabolites responsible for mitochondrial functions. For these reasons, VDACs contribute to mitochondrial quality control and the entire energy metabolism of the cell. In this work we assessed in an ALS cell model whether disease-related oxidative stress induces post-translational modifications (PTMs) in VDAC3, a member of the VDAC family of outer mitochondrial membrane channel proteins, known for its role in redox signaling. At this end, protein samples enriched in VDACs were prepared from mitochondria of an ALS model cell line, NSC34 expressing human SOD1G93A, and analyzed by nUHPLC/High-Resolution nESI-MS/MS. Specific over-oxidation, deamidation, succination events were found in VDAC3 from ALS-related NSC34-SOD1G93A but not in non-ALS cell lines. Additionally, we report evidence that some PTMs may affect VDAC3 functionality. In particular, deamidation of Asn215 alone alters single channel behavior in artificial membranes. Overall, our results suggest modifications of VDAC3 that can impact its protective role against ROS, which is particularly important in the ALS context. Data are available via ProteomeXchange with identifier PXD036728.
Insights
Oxidative stress in amyotrophic lateral sclerosis (ALS) modifies VDAC3, a mitochondrial protein. These changes, including oxidation and deamidation, may impair its protective function against reactive oxygen species (ROS), impacting ALS progression.
Area of Science:
- Mitochondrial biology
- Neuroscience
- Biochemistry
Background:
- Oxidative stress is a major factor in motor neuron death in amyotrophic lateral sclerosis (ALS).
- Mitochondria produce and are damaged by reactive oxygen species (ROS), influencing cellular energy metabolism.
- Voltage-dependent anion-selective channels (VDACs) in the outer mitochondrial membrane regulate metabolite transport and mitochondrial function.
Purpose of the Study:
- To investigate if oxidative stress in an ALS cell model induces post-translational modifications (PTMs) in VDAC3.
- To determine if these PTMs affect VDAC3 functionality and its role in redox signaling.
Main Methods:
- Utilized an ALS cell model (NSC34 expressing human SOD1G93A) to isolate VDAC-enriched mitochondrial proteins.
- Employed nano-Ultra-High-Performance Liquid Chromatography/High-Resolution Electrospray Ionization Tandem Mass Spectrometry (nUHPLC/High-Resolution nESI-MS/MS) for protein analysis.
Main Results:
- Identified specific over-oxidation, deamidation, and succination events in VDAC3 from the ALS cell line.
- Observed no such modifications in non-ALS cell lines.
- Demonstrated that deamidation of Asn215 in VDAC3 alters its single-channel behavior in artificial membranes.
Conclusions:
- Disease-related oxidative stress induces PTMs in VDAC3 in an ALS cellular context.
- These VDAC3 modifications may compromise its protective role against ROS, potentially contributing to ALS pathogenesis.
- Findings highlight VDAC3 as a potential target for understanding and treating ALS.
