VDAC1 (voltage-dependent anion channel 1)

2012-03-01   Varda Shoshan-Barmatz  , Dario Mizrachi  

Department of Life Sciences, the National Institute for Biotechnology in the Neguev (NIBN), Ben-Gurion University, Beer-Sheva, Israel

Identity

HGNC
LOCATION
5q31.1
LOCUSID
ALIAS
PORIN,VDAC-1
FUSION GENES

DNA/RNA

Description

The gene encompasses over 33 kb of DNA; 9 exons.

Transcription

There are 3 splice variants reported but they all encode the same 282 amino acids protein. One transcript variant has an mRNA product length of 1993 bp (accession number: NM_003374). Processed length 852 bp.

Proteins

Description

Voltage-dependent anion-selective channel protein 1 (VDAC1, accession number: NP_003365.1) encodes for a protein product length of 283. VDAC1 regulates the flux of mostly anionic metabolites through the outer mitochondrial membrane, which is highly permeable to small molecules. VDAC is the most abundant protein in the outer membrane. Changes in membrane potentials can switch VDAC between open or high-conducting and closed or low-conducting forms.
Atlas Image
Schematic representation of VDAC1 inserted in the membrane. The image was prepared using the crystal structure of mouse VDAC1, PDB ID 3emn (PDB).

Expression

Mitochondrial porins have been found in all eukaryotic cells studied to date. In mammalian tissues VDAC1 is expressed in many normal and tumour tissues. It has been well characterized in brain, heart, skeletal muscle, and liver. Human cancer cell lines express higher VDAC1 levels than normal cells (Shinohara et al., 2000; Sinamura et al., 2006; Sinamura et al., 2008).

Localisation

Primarily in the Outer Mitochondrial Membrane (OMM), but in erythrocytes cell death events (eryptosis) it has been found in the plasma membrane (Sridharan et al., 2012).

Function

VDAC1, located at the OMM, is a key protein in regulating the exchange of ions, nucleotides and a variety of metabolites in and out of the mitochondria. As such, VDAC1 serves a crucial role in cellular energy maintenance. It provides a permeation pathway for metabolites and mobile ions between the cytosol and mitochondria. VDACs are also involved in cell death by interacting with apoptotic proteins and releasing apoptotic metabolites to the cytosol.
Protein modifications. VDAC1 has been shown to be phosphorylated in multiple sites: serine, threonine, and tyrosine. Some candidate kinases have been suggested: GSK3, CaM-II, CKI, PKA, PKC, cdc2, p38MAPK, Nek1, EGFR, and SRC. Following reconstitution of VDAC1 into planar lipid bilayers, phosphorylation by PKA reduces the channel current. In rat liver OMM the N-terminal methionine from VDAC1 is removed and the new amino terminal alanine is acetylated. Two separate studies demonstrated that VDAC1 was multiply acetylated in mouse liver, each study reported different sites. VDAC1 is ubiquitinated following mitochondrial depolarization (Narendra et al., 2010).
Protein interactions. Localization of VDAC1 to the OMM makes it a functional anchor point for molecules that interact with the mitochondria. VDAC1 displays binding sites for glycerol kinase, hexokinase (HK), creatine kinase, mitochondrial creatine kinase (MtCK) (interacts with VDAC1 competing with HK and Bax). VDAC also forms complexes with other proteins, such as the ANT, the peripheral benzodiazepine receptor (TSPO), tubulin, the dynein light chain, mtHSP70, the ORDIC channel, glyceraldehyde 3-phosphate dehydrogenase, actin and gelsolin, as well as with apoptosis-regulating proteins, such as members of the Bcl-2 family.
VDAC1 oligomerization. VDAC1 has been shown to assemble into dimers, trimers, tetramers, and higher oligomeric states in a dynamic process, including the VDAC1 purified from liver mitochondria, recombinant human VDAC, and liver or brain mitochondrion-embedded VDAC1. The supramolecular organization of VDAC1 has also been demonstrated using Atomic Force Microscope. Oligomeric assembly of VDAC1 has been shown to be coupled to apoptosis induction, with oligomerization increasing substantially upon apoptosis induction and inhibited by apoptosis blockers.
N-terminal domain. The N-terminus of VDAC1 is 25 amino acids long, and contains an alpha helix (between residues 5-16). In recently published 3-D structures the N-terminus resides within the pore; independent studies show that it could move out of the pore. The N-terminal α-helical segment is proposed to be involved in channel gating, where it could be acting as the voltage sensor and possibly regulating the conductance of ions and metabolites through the VDAC1 pore. VDAC1-N-terminus is required for apoptosis induction, its interaction with HK-I and Bcl2 has a protective effect against apoptosis (Arbel and Shoshan-Barmatz, 2009).

Homology

In higher eukaryotes, three VDAC isoforms have been characterized: VDAC1, VDAC2 and VDAC3, encoded by three separate genes. VDACs are highly conserved across species. VDAC1 is the most abundant isoform in most cells, being ten times more prevalent than VDAC2 and 100 times more prevalent than VDAC3 in HeLa cells (De Pinto et al., 2010). Recently it was demonstrated that while VDAC1 and VDAC2 are localized mainly within the same distinct domains of the OMM, VDAC3 is mostly distributed uniformly over the surface of the mitochondrion.

Mutations

Somatic

Direct DNA sequencing of colorectal cancer (CRC) and gastric cancer (GC) led to identification of a recurrent VDAC1 mutation. This mutation, c.332delA, leads to a premature stop codon, resulting in truncation of the amino acid synthesis (p.Asn111MetfsX34) and would remove about 60% length of C-terminal VDAC1 protein. The DNA sequencing indicated that the mutation was heterozygous. There was no significant difference of the mutations with respect to the clinicopathologic features of the GC and CRC (Fishers exact test, p>0,05) (Yoo et al., 2011).

Implicated in

Entity name
VDAC1 and cancer
Note
Hexokinase (HK) interacts with VDAC to mediate its anti-apoptotic activity. It has been reported that human cancer cell lines express higher VDAC1 levels than normal cells, while mitochondria from malignant tumor cell lines are capable of higher HK binding, thus increasing protection against apoptosis. The HK-VDAC interaction is thought to underlie cell survival and apoptosis regulation by HK.
A) HK bound to VDAC on the mitochondrial surface provides metabolic benefit that offers the cell a proliferative advantage.
B) HK-I and HK-II binding to VDAC1 protects against apoptosis, with their release enabling activation of apoptosis.
C) HK was shown to reduce mitochondrial reactive oxygen species (ROS) generation through an ADP-recycling mechanism. Accordingly, detachment of HK from VDAC1 could lead to increased H2O2 generation and release to the cytoplasm, thereby activating cell death.
D) The interaction of HK with VDAC protects against activation of apoptosis by BCL2-associated X protein (Bax) or Bcl-2 homologous antagonist/killer (Bak). Thus, VDAC-bound HK renders cells much more resistant to apoptosis.
Entity name
Rare mitochondrial encephalomyopathy
Note
Tissue-specific VDAC isoform 1 (HVDAC1) deficiency in human skeletal muscle is responsible for a rare mitochondrial encephalomyopathy, fatal in childhood (Messina et al., 1999).
Entity name
Neurodegenerative diseases
Note
Protein level changes of VDAC1 in brain of patients with Alzheimers disease and Down syndrome have been reported (Yoo et al., 2001).
Although evidence supporting a role for VDAC in the pathogenesis of Alzheimers disease (AD) exists, its precise contribution is unknown. It has been suggested that VDAC may be involved in membrane dysfunction associated with AD neuropathology. The extent of oxidative damage to VDAC was reflected in the increase in nitrated VDAC1 in AD. VDAC modifications may alter VDAC-mediated bidirectional energy fluxes across the mitochondrial membrane. VDAC has been studied in Downs syndrome patients, epilepsy animal models, in dopamine-induced apoptosis, and amyotrophic lateral sclerosis (ALS). The involvement of VDAC in numerous pathological conditions may result from disturbed VDAC function in energy production, metabolite cross-talk between the cytosol and the mitochondria, or apoptosis regulation.
Entity name
Muscular and myocardial diseases
Note
In a rabbit model for myocardial ischemia and reperfusion, it was demonstrated that the p38 MAPK inhibitor, PD169316, significantly reduced p38-mediated phosphorylation of VDAC1, implicating VDAC1 in myocardial ischemia and reperfusion.
Entity name
VDAC and reagent toxicity
Note
ROS are known to activate apoptosis. In addition, ROS appears to activate VDAC. Furanonaphthoquinones (FNQs) were proposed to induce apoptosis via ROS. The ROS production and the anti-cancer activity of FNQs were increased upon VDAC1 overexpression and decreased upon silencing VDAC1 expression by siRNA.
There are other chemicals that directly interact with and modify VDACs activity. G3139 (oblimersen), an 18-mer phosphorothioate anti-sense oligonucleotide targeted to the initiation codon region of Bcl-2 mRNA, directly binds and reduces the channel conductance of bilayer-reconstituted VDAC. Avicins represent a novel class of plant stress metabolites that exhibit cytotoxic activity in tumor cells, as well as anti-inflammatory and anti-oxidant properties capable of perturbing mitochondrial function and initiating apoptosis in tumor cells. Fluoxetine (Prozac), a clinically-used anti-depressant compound which acts on multiple transporters and channels, enhanced cell proliferation and prevented or enhanced apoptosis in various cell lines. Fluoxetine was shown to interact directly with VDAC and inhibit apoptosis. Cisplatin is a widely used anti-cancer drug which acts by inducing apoptosis. Cisplatin binds and modulates VDACs activity (Yang et al., 2006) to modulate VDAC1 activity. Acrolein (2-propen-1-al), the most reactive of the α,β-unsaturated aldehydes and a toxic compound. VDAC was recently identified as a selectively oxidized target in the AD brain, being significantly carbonylated by acrolein. Endostatin (ES) has been shown to promote the permeability transition pore (PTP) opening via VDAC. Silencing VDAC1 expression by siRNA attenuates ES-induced apoptosis, while overexpression of VDAC1 enhances the sensitivity of endothelial cells to ES.

Article Bibliography

Pubmed IDLast YearTitleAuthors

Other Information

Locus ID:

NCBI: 7416
MIM: 604492
HGNC: 12669
Ensembl: ENSG00000213585

Variants:

dbSNP: 7416
ClinVar: 7416
TCGA: ENSG00000213585
COSMIC: VDAC1

RNA/Proteins

Gene IDTranscript IDUniprot
ENSG00000213585ENST00000265333P21796
ENSG00000213585ENST00000265333A0A1L1UHR1
ENSG00000213585ENST00000395044P21796
ENSG00000213585ENST00000395044A0A1L1UHR1
ENSG00000213585ENST00000395047P21796
ENSG00000213585ENST00000395047A0A1L1UHR1
ENSG00000213585ENST00000425992C9JI87

Expression (GTEx)

0
50
100
150
200
250
300
350
400
450

Pathways

PathwaySourceExternal ID
Calcium signaling pathwayKEGGko04020
Huntington's diseaseKEGGko05016
Calcium signaling pathwayKEGGhsa04020
Parkinson's diseaseKEGGhsa05012
Huntington's diseaseKEGGhsa05016
NOD-like receptor signaling pathwayKEGGko04621
NOD-like receptor signaling pathwayKEGGhsa04621
Influenza AKEGGko05164
Influenza AKEGGhsa05164
HTLV-I infectionKEGGko05166
HTLV-I infectionKEGGhsa05166
cGMP-PKG signaling pathwayKEGGhsa04022
cGMP-PKG signaling pathwayKEGGko04022
Metabolism of proteinsREACTOMER-HSA-392499
Post-translational protein modificationREACTOMER-HSA-597592
Mitochondrial protein importREACTOMER-HSA-1268020
MitophagyREACTOMER-HSA-5205647
Pink/Parkin Mediated MitophagyREACTOMER-HSA-5205685
DeubiquitinationREACTOMER-HSA-5688426
Ub-specific processing proteasesREACTOMER-HSA-5689880

Protein levels (Protein atlas)

Not detected
Low
Medium
High

References

Pubmed IDYearTitleCitations
377022302024Mitochondrial Calcium Uniporter (MCU) that Modulates Mitochondrial Calcium Uptake and Facilitates Endometrial Cancer Progression through Interaction with VDAC1.2
377375172024Identification and validation of voltage-dependent anion channel 1-related genes and immune cell infiltration in diabetic nephropathy.1
380708602024The inhibition of VDAC1 oligomerization promotes pigmentation through the CaMK-CRTCs/CREB-MITF pathway.0
377022302024Mitochondrial Calcium Uniporter (MCU) that Modulates Mitochondrial Calcium Uptake and Facilitates Endometrial Cancer Progression through Interaction with VDAC1.2
377375172024Identification and validation of voltage-dependent anion channel 1-related genes and immune cell infiltration in diabetic nephropathy.1
380708602024The inhibition of VDAC1 oligomerization promotes pigmentation through the CaMK-CRTCs/CREB-MITF pathway.0
366423192023ANP32B promotes lung cancer progression by regulating VDAC1.1
366582272023Site-specific ubiquitination of VDAC1 restricts its oligomerization and mitochondrial DNA release in liver fibrosis.6
367501732023miRNA-874-3p inhibits the migration, invasion and proliferation of breast cancer cells by targeting VDAC1.3
368032352023Hypoxia-induced GPCPD1 depalmitoylation triggers mitophagy via regulating PRKN-mediated ubiquitination of VDAC1.7
368351022023VDAC1 Knockout Affects Mitochondrial Oxygen Consumption Triggering a Rearrangement of ETC by Impacting on Complex I Activity.5
368716362023Prognosis-related VDAC1 regulates the proliferation and apoptosis of osteosarcoma cells via the MAPK signaling pathway.1
369794922023Ablation of GPR56 Causes β-Cell Dysfunction by ATP Loss through Mistargeting of Mitochondrial VDAC1 to the Plasma Membrane.0
370107212023Evaluation of copper-induced biomolecular changes in different porin mutants of Escherichia coli W3110 by infrared spectroscopy.2
372218352023Evolution of Mycobacterium abscessus in the human lung: Cumulative mutations and genomic rearrangement of porin genes in patient isolates.1

Citation

Varda Shoshan-Barmatz ; Dario Mizrachi

VDAC1 (voltage-dependent anion channel 1)

Atlas Genet Cytogenet Oncol Haematol. 2012-03-01

Online version: http://atlasgeneticsoncology.org/gene/50902/haematological-explorer/js/gene-fusions-explorer/