Manganese-dependent superoxide dismutase localized to the mitochondrial matrix. SOD2 catalyzes the dismutation of superoxide radicals (O2•−) to hydrogen peroxide and molecular oxygen, serving as a critical antioxidant defense mechanism against reactive oxygen species generated during mitochondrial respiration. The enzyme contains one manganese ion per subunit and functions as a homotetramer.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
|
GO:0005739
mitochondrion
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: IBA annotation for mitochondrial localization based on phylogenetic inference across orthologous SOD2 proteins. Well-supported by multiple direct experimental observations confirming mitochondrial matrix localization.
Reason: SOD2 is a well-established mitochondrial protein. The mitochondrial localization is supported by extensive evidence including direct biochemical purification from mitochondria, subcellular fractionation studies, and the presence of a mitochondrial transit peptide (residues 1-26) that is cleaved upon import. IBA inference from orthologous sequences is appropriate for this annotation as SOD2 localization is conserved across eukaryotes.
Supporting Evidence:
PMID:238997
The cyanide-insensitive superoxide dismutase of yeast has been shown to be localized in the mitochondrial matrix.
PMID:15851472
Manganese-dependent superoxide dismutase 2 (SOD2) in the mitochondria plays a key role in protection against oxidative stress.
|
|
GO:0004784
superoxide dismutase activity
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: IBA annotation for superoxide dismutase catalytic activity, inferred from orthologous SOD2 proteins. Core molecular function of SOD2 and highly conserved across eukaryotes. This annotation is more specific and appropriate than broader "oxidoreductase activity" annotations.
Reason: SOD2's primary molecular function is superoxide dismutase activity. The enzyme catalyzes conversion of superoxide anion to hydrogen peroxide and oxygen (EC 1.15.1.1). This is a highly specific and informative functional annotation representing the core catalytic activity. IBA inference is appropriate given the high conservation of this enzyme family across eukaryotes and consistent functional characterization of SOD2 orthologs.
Supporting Evidence:
PMID:238997
This enzyme has been isolated in good yield from bakers' yeast...This enzyme has activity comparable to that of other previously reported superoxide dismutases
PMID:15851472
Manganese-dependent superoxide dismutase 2 (SOD2) in the mitochondria plays a key role in protection against oxidative stress
file:yeast/SOD2/SOD2-deep-research-falcon.md
Falcon literature synthesis supports SOD2 as the mitochondrial manganese superoxide dismutase that detoxifies superoxide generated during respiration.
file:interpro/panther/PTHR11404/PTHR11404-metadata.yaml
PANTHER PTHR11404 identifies SOD2 in the iron/manganese superoxide dismutase family.
|
|
GO:0030145
manganese ion binding
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: IBA annotation for manganese ion binding cofactor requirement. SOD2 requires manganese for catalytic activity with 1 Mn2+ per subunit. Critical for enzyme function and essential for distinguishing from cytoplasmic Fe-SOD1.
Reason: SOD2 is a manganese-dependent superoxide dismutase, distinguishing it from the iron-dependent SOD1 isoform found in the cytoplasm. The UniProt entry explicitly states "Binds 1 Mn(2+) ion per subunit" with specific binding residues identified (positions 52, 107, 194, 198). Manganese insertion is essential during import into mitochondria and is mechanistically coupled to the mitochondrial import process. This annotation is more specific and informative than generic "metal ion binding" annotations and reflects the specialized cofactor requirement.
Supporting Evidence:
PMID:238997
This enzyme contains 1 atom of manganese per subunit and its absorption in the visible suggests Mn(III) in the resting enzyme.
PMID:15851472
We found that a mitochondrial localization is essential...Manganese insertion is only possible with a newly synthesized polypeptide.
|
|
GO:0004784
superoxide dismutase activity
|
IEA
GO_REF:0000120 |
ACCEPT |
Summary: IEA annotation via InterPro mapping (IPR001189: Mn/Fe superoxide dismutase). Redundant with IBA and IDA annotations for the same function but from automated computational mapping. Acceptable but less evidence-rich than experimental data.
Reason: This IEA annotation derives from InterPro domain mapping, which appropriately identifies SOD2 as a superoxide dismutase based on conserved protein domains. While less informative than direct experimental evidence, automated annotations based on InterPro are generally reliable for well-characterized enzyme families. The annotation is not contradicted by experimental evidence and supports the core function identified by IBA and IDA annotations.
Supporting Evidence:
GO_REF:0000120
Combined Automated Annotation using Multiple IEA Methods based on InterPro domain mapping
|
|
GO:0005739
mitochondrion
|
IEA
GO_REF:0000117 |
ACCEPT |
Summary: IEA annotation for mitochondrial localization via ARBA machine learning models. Represents automated inference from amino acid sequence patterns associated with mitochondrial proteins. Redundant with direct experimental evidence.
Reason: ARBA machine learning models provide evidence for mitochondrial localization based on sequence patterns trained on experimentally validated mitochondrial proteins. While less directly informative than experimental evidence, this IEA annotation is consistent with and supported by extensive experimental data including direct biochemical purification and subcellular localization studies.
|
|
GO:0005759
mitochondrial matrix
|
IEA
GO_REF:0000044 |
ACCEPT |
Summary: IEA annotation based on UniProtKB subcellular location vocabulary mapping to "Mitochondrion matrix". More specific than broader "mitochondrion" annotation, reflecting SOD2's precise subcellular compartment.
Reason: The annotation correctly identifies the mitochondrial matrix as SOD2's specific subcellular compartment. This IEA is derived from structured UniProtKB annotation and is supported by direct experimental evidence. The matrix localization is essential for SOD2 function in protecting mitochondrial proteins and DNA from superoxide generated by the electron transport chain. This is more specific and informative than the broader "mitochondrion" annotations.
Supporting Evidence:
PMID:238997
The cyanide-insensitive superoxide dismutase of yeast has been shown to be localized in the mitochondrial matrix.
|
|
GO:0006801
superoxide metabolic process
|
IEA
GO_REF:0000002 |
ACCEPT |
Summary: IEA annotation for involvement in superoxide metabolic process based on InterPro domain mapping. Reasonable but somewhat redundant with more specific process annotations like "removal of superoxide radicals".
Reason: This annotation appropriately captures SOD2's involvement in superoxide metabolism through the dismutation reaction. However, it is broader than the more specific functional process "removal of superoxide radicals" (GO:0019430) which more precisely describes the biological outcome. The annotation is not incorrect but represents a higher-level categorization of the more specific process.
|
|
GO:0016209
antioxidant activity
|
IEA
GO_REF:0000043 |
ACCEPT |
Summary: IEA annotation based on UniProtKB keyword mapping (KW-0049: Antioxidant). Accurate but relatively broad characterization of SOD2's functional role.
Reason: SOD2 is correctly characterized as having antioxidant activity through its superoxide dismutase function. While this annotation is less specific than GO:0004784 (superoxide dismutase activity), it is accurate and captures the physiological consequence of the enzyme's catalytic activity. Antioxidant activity represents an appropriate functional categorization for SOD2.
|
|
GO:0016491
oxidoreductase activity
|
IEA
GO_REF:0000043 |
KEEP AS NON CORE |
Summary: IEA annotation based on UniProtKB keyword mapping (KW-0560: Oxidoreductase). Correct but very broad categorization of enzymatic function.
Reason: While technically correct that superoxide dismutase is an oxidoreductase enzyme (catalyzing electron transfer in the dismutation reaction), this annotation is overly broad and lacks specificity. The broader "oxidoreductase activity" encompasses thousands of diverse enzymatic activities and provides minimal functional information. More specific annotations like "superoxide dismutase activity" and "antioxidant activity" are far more informative. However, it is not incorrect, so retaining it as non-core is appropriate to avoid cluttering the functional annotation space.
|
|
GO:0019430
removal of superoxide radicals
|
IEA
GO_REF:0000108 |
ACCEPT |
Summary: IEA annotation inferred via logical inference from the primary superoxide dismutase activity annotation. Accurately captures the functional consequence of SOD2's enzymatic activity.
Reason: This process annotation appropriately captures the biological function of SOD2. The enzyme removes/detoxifies superoxide radicals by catalyzing their conversion to hydrogen peroxide and oxygen. This is the functional outcome of the superoxide dismutase catalytic activity and is logically inferred from that core function. The annotation is supported by extensive evidence of SOD2's role in cellular antioxidant defense.
Supporting Evidence:
PMID:3520557
MnSOD contributes to the natural protection of cells against oxygen toxicity
|
|
GO:0046872
metal ion binding
|
IEA
GO_REF:0000120 |
KEEP AS NON CORE |
Summary: IEA annotation for general metal ion binding based on InterPro domain mapping. Accurate but very broad and less specific than the manganese-specific annotation.
Reason: SOD2 does bind a metal ion (specifically manganese), making this annotation technically correct. However, it is overly general and lacks the specificity that makes GO:0030145 (manganese ion binding) superior. While some genes may require annotation at this level of generality, SOD2's cofactor requirement is specifically and characteristically for manganese rather than other metal ions. The more specific "manganese ion binding" annotation is far more informative and should be prioritized. Retaining this as non-core avoids redundancy.
|
|
GO:0098869
cellular oxidant detoxification
|
IEA
GO_REF:0000108 |
ACCEPT |
Summary: IEA annotation for cellular oxidant detoxification, inferred from antioxidant activity via logical inference. Captures the cellular process consequence of SOD2's enzymatic function.
Reason: This process annotation appropriately characterizes SOD2's role in protecting cells from reactive oxygen species. The enzyme detoxifies superoxide and contributes to overall cellular antioxidant defense. The annotation is logically inferred from the antioxidant activity function and is supported by experimental evidence of SOD2's essential role in protecting cells against oxidative stress, particularly in mitochondria where high ROS levels are generated.
|
|
GO:0005739
mitochondrion
|
HDA
PMID:24769239 Quantitative variations of the mitochondrial proteome and ph... |
ACCEPT |
Summary: HDA annotation from quantitative proteomic study identifying SOD2 in isolated mitochondria during proteomic survey of mitochondrial proteins under different growth conditions. Supports mitochondrial localization.
Reason: This HDA annotation is based on direct detection of SOD2 protein in isolated mitochondrial fractions using mass spectrometry. Quantitative proteomics provides strong evidence for protein localization. The study systematically identified mitochondrial proteins and their relative abundance across different metabolic conditions. This represents solid experimental evidence for mitochondrial presence, though less specific than subcellular fractionation at the matrix level.
Supporting Evidence:
PMID:24769239
Label free quantitative analysis of protein accumulation revealed significant variation of 176 mitochondrial proteins
|
|
GO:0005739
mitochondrion
|
HDA
PMID:11914276 Subcellular localization of the yeast proteome. |
ACCEPT |
Summary: HDA annotation from proteome-scale high-throughput subcellular localization study mapping yeast protein localization. Confirms mitochondrial localization through immunolocalization-based approach.
Reason: This study represents the first large-scale proteome localization study in yeast, using high-throughput immunolocalization of epitope-tagged proteins to determine subcellular localization. SOD2 was identified among proteins localized to mitochondria in the GOA HDA record. The locally cached publication text contains the study abstract and methodology but not the SOD2-specific table entry, so this review cites the PMID-level method and treats matrix-specific localization as requiring additional evidence.
Supporting Evidence:
PMID:11914276
By high-throughput immunolocalization of tagged gene products, we have determined the subcellular localization of 2744 yeast proteins.
|
|
GO:0005739
mitochondrion
|
HDA
PMID:14576278 The proteome of Saccharomyces cerevisiae mitochondria. |
ACCEPT |
Summary: HDA annotation from comprehensive mass spectrometry-based proteomics of purified yeast mitochondria. SOD2 identified in mitochondrial proteome catalog.
Reason: This landmark study identified >750 different proteins from highly purified yeast mitochondria using tandem mass spectrometry. SOD2 was identified in this comprehensive mitochondrial proteome. The study analyzed only mitochondrial fractions, providing direct evidence for mitochondrial localization. This represents strong experimental support from a well-cited mitochondrial proteomics resource.
Supporting Evidence:
PMID:14576278
From >20 million MS spectra, 750 different proteins were identified, indicating an involvement of mitochondria in numerous cellular processes
|
|
GO:0005739
mitochondrion
|
HDA
PMID:16823961 Toward the complete yeast mitochondrial proteome: multidimen... |
ACCEPT |
Summary: HDA annotation from advanced proteomics study combining multidimensional separation techniques to characterize the complete yeast mitochondrial proteome.
Reason: This study used orthogonal proteomics approaches to achieve the most comprehensive characterization of the yeast mitochondrial proteome, identifying 851 different proteins. SOD2 was identified as a mitochondrial protein in this resource. The use of multiple complementary separation and detection methods increases confidence in protein identification. This represents high-quality experimental evidence for mitochondrial localization from a mature proteomics platform.
Supporting Evidence:
PMID:16823961
A total of 851 different proteins (PROMITO dataset) were identified by use of multidimensional LC-MS/MS
|
|
GO:0004784
superoxide dismutase activity
|
IDA
PMID:15851472 Manganese activation of superoxide dismutase 2 in the mitoch... |
ACCEPT |
Summary: IDA annotation from direct enzymatic assay study characterizing manganese activation of SOD2 in mitochondria. Demonstrates enzyme activity and essential cofactor requirement.
Reason: This IDA annotation is from direct biochemical characterization of SOD2 enzyme activity in mitochondrial context. The study specifically examined manganese activation of SOD2, demonstrating the enzyme's superoxide dismutase activity and its dependence on mitochondrial import for proper cofactor insertion. This represents strong experimental evidence for the core molecular function.
Supporting Evidence:
PMID:15851472
Manganese-dependent superoxide dismutase 2 (SOD2) in the mitochondria plays a key role in protection against oxidative stress. Here we probed the pathway by which SOD2 acquires its manganese catalytic cofactor.
|
|
GO:0004784
superoxide dismutase activity
|
IDA
PMID:238997 Isolation and characterization of a manganese-containing sup... |
ACCEPT |
Summary: IDA annotation from the landmark 1975 study that first isolated and characterized manganese-containing SOD from yeast. Original biochemical characterization of enzyme activity.
Reason: This is from the seminal study that first isolated yeast mitochondrial SOD and demonstrated its superoxide dismutase activity in vitro. The study characterized the enzyme's molecular weight (96,000 Da tetramer), subunit structure, manganese content (1 Mn per subunit), and catalytic activity. This represents foundational experimental evidence for SOD2's molecular function and remains a critical reference for the enzyme's properties.
Supporting Evidence:
PMID:238997
This enzyme has been isolated in good yield from bakers' yeast...This enzyme contains 1 atom of manganese per subunit...This enzyme has activity comparable to that of other previously reported superoxide dismutases
|
|
GO:0005739
mitochondrion
|
IDA
PMID:15851472 Manganese activation of superoxide dismutase 2 in the mitoch... |
ACCEPT |
Summary: IDA annotation from manganese activation study that demonstrated SOD2's mitochondrial localization is essential for cofactor insertion and activation.
Reason: The study directly showed that mitochondrial localization of SOD2 is essential for proper manganese insertion and enzyme activation. Cytosolic versions of SOD2 remain largely apo (without manganese) unless cells are exposed to toxic manganese levels. This demonstrates mechanistically that SOD2's mitochondrial localization is not just coincidental but essential for function. The study provides strong experimental evidence for mitochondrial localization integrated with functional characterization.
Supporting Evidence:
PMID:15851472
We found that a mitochondrial localization is essential...By reversibly blocking mitochondrial import in vivo, we noted that newly synthesized Sod2p can enter mitochondria but not a Sod2p polypeptide that was allowed to accumulate in the cytosol.
|
|
GO:0005759
mitochondrial matrix
|
IDA
PMID:238997 Isolation and characterization of a manganese-containing sup... |
ACCEPT |
Summary: IDA annotation from original characterization study that specifically localized the enzyme to the mitochondrial matrix compartment. Foundational evidence for subcellular compartmentalization.
Reason: The seminal 1975 study explicitly localized the cyanide-insensitive (manganese) superoxide dismutase to the mitochondrial matrix, the innermost mitochondrial compartment where the electron transport chain generates superoxide and where SOD2 provides essential antioxidant protection. This specific subcellular localization is more informative than broader mitochondrion annotations and accurately reflects the enzyme's functional compartment. This remains the gold standard evidence for matrix localization.
Supporting Evidence:
PMID:238997
The cyanide-insensitive superoxide dismutase of yeast has been shown to be localized in the mitochondrial matrix.
|
|
GO:0072593
reactive oxygen species metabolic process
|
IMP
PMID:3520557 A yeast mutant lacking mitochondrial manganese-superoxide di... |
ACCEPT |
Summary: IMP annotation from genetic knockout study demonstrating that SOD2 is essential for cellular protection against oxygen-induced ROS toxicity. Establishes biological role in ROS metabolism.
Reason: This IMP annotation is from a landmark genetic study that created a SOD2-null mutant and demonstrated its hypersensitivity to oxygen. The mutant lacked cyanide-insensitive SOD activity and exhibited growth inhibition in oxygen-containing atmospheres, providing direct genetic evidence that SOD2 contributes to cellular defense against oxygen toxicity through ROS metabolism. This represents the strongest type of biological process evidence showing that loss of protein function impairs the process.
Supporting Evidence:
PMID:3520557
In the absence of oxygen, the mutant grew as rapidly as the wild-type parent. However, increasing concentrations of oxygen led to a progressive inhibition of growth. The properties of this mutant provide direct evidence that MnSOD contributes to the natural protection of cells against oxygen toxicity.
|
Q: What role does SOD2 phosphorylation play in regulating its activity or localization?
Q: Are there condition-specific changes in SOD2 expression or activity in response to metabolic state?
Q: Does SOD2 interact with other mitochondrial proteins to form a larger antioxidant defense complex?
Experiment: Detailed kinetic analysis of SOD2 with various superoxide concentrations and pH conditions to establish optimal activity parameters in vivo
Experiment: Investigation of SOD2 regulation by reactive oxygen species or other cellular signals that might modulate its expression
Experiment: Analysis of the relationship between SOD2 activity and cellular aging or replicative lifespan in yeast
provider: falcon
model: Edison Scientific Literature
cached: false
start_time: '2026-05-04T10:58:40.372860'
end_time: '2026-05-04T11:17:35.385520'
duration_seconds: 1135.01
template_file: templates/gene_research_go_focused.md
template_variables:
organism: yeast
gene_id: SOD2
gene_symbol: SOD2
uniprot_accession: P00447
protein_description: 'RecName: Full=Superoxide dismutase [Mn], mitochondrial; EC=1.15.1.1
{ECO:0000250|UniProtKB:P0A0J3}; Flags: Precursor;'
gene_info: Name=SOD2; OrderedLocusNames=YHR008C;
organism_full: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast).
protein_family: Belongs to the iron/manganese superoxide dismutase family.
protein_domains: Fe/Mn_Superoxide_Dismutase. (IPR050265); Mn/Fe_SOD. (IPR001189);
Mn/Fe_SOD_BS. (IPR019833); Mn/Fe_SOD_C. (IPR019832); Mn/Fe_SOD_N. (IPR019831)
provider_config:
timeout: 600
max_retries: 3
parameters:
allowed_domains: []
temperature: 0.1
citation_count: 32
BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.
DO NOT PROCEED WITH RESEARCH ON A DIFFERENT GENE. Instead:
- State clearly: "The gene symbol 'SOD2' is ambiguous or literature is limited for this specific protein"
- Explain what you found (e.g., "Found extensive literature on a different gene with the same symbol in a different organism")
- Describe the protein based ONLY on the UniProt information provided above
- Suggest that the protein function can be inferred from domain/family information
Please provide a comprehensive research report on the gene SOD2 (gene ID: SOD2, UniProt: P00447) in yeast.
The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.
You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.
We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.
We are interested in where in or outside the cell the gene product carries out its function.
We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.
Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.
Question: You are an expert researcher providing comprehensive, well-cited information.
Provide detailed information focusing on:
1. Key concepts and definitions with current understanding
2. Recent developments and latest research (prioritize 2023-2024 sources)
3. Current applications and real-world implementations
4. Expert opinions and analysis from authoritative sources
5. Relevant statistics and data from recent studies
Format as a comprehensive research report with proper citations. Include URLs and publication dates where available.
Always prioritize recent, authoritative sources and provide specific citations for all major claims.
BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.
DO NOT PROCEED WITH RESEARCH ON A DIFFERENT GENE. Instead:
- State clearly: "The gene symbol 'SOD2' is ambiguous or literature is limited for this specific protein"
- Explain what you found (e.g., "Found extensive literature on a different gene with the same symbol in a different organism")
- Describe the protein based ONLY on the UniProt information provided above
- Suggest that the protein function can be inferred from domain/family information
Please provide a comprehensive research report on the gene SOD2 (gene ID: SOD2, UniProt: P00447) in yeast.
The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.
You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.
We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.
We are interested in where in or outside the cell the gene product carries out its function.
We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.
Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.
Saccharomyces cerevisiae SOD2 (YHR008C; UniProt P00447) encodes the mitochondrial matrix manganese superoxide dismutase (MnSOD/Sod2p) that catalyzes superoxide dismutation to hydrogen peroxide and oxygen and is essential for mitochondrial redox homeostasis and multiple downstream stress-adaptation processes (gupta2023mitochondrialsuperoxidedismutase pages 1-2, grujicic2025manganesesuperoxidedismutase pages 1-3). Beyond detoxification, yeast Sod2p can act upstream of redox signaling (e.g., via H2O2-dependent activation of Yap1 during ethanol stress) and, in recent work, suppresses nuclear genome instability during paraquat-induced oxidative stress, connecting mitochondrial redox state to nuclear DNA integrity (zyrina2017mitochondrialsuperoxidedismutase pages 11-13, gupta2023mitochondrialsuperoxidedismutase pages 1-2).
The target described by UniProt P00447 corresponds to SOD2 / YHR008C in S. cerevisiae (S288c) and is explicitly described in multiple sources as:
- a mitochondrial matrix protein (gupta2023mitochondrialsuperoxidedismutase pages 1-2, maslanka2020linkagebetweencarbon pages 1-3)
- the manganese-dependent superoxide dismutase (MnSOD) (gupta2023mitochondrialsuperoxidedismutase pages 1-2, stepien2020impactofcurcumin pages 1-3)
- distinct from yeast SOD1, which is primarily cytosolic and also present in the mitochondrial intermembrane space (gupta2023mitochondrialsuperoxidedismutase pages 1-2, maslanka2020linkagebetweencarbon pages 1-3)
These statements match the UniProt description “Superoxide dismutase [Mn], mitochondrial; precursor” and the Fe/Mn SOD family/domain assignment.
Mitochondrial respiration is a major endogenous source of superoxide (O2•−), a reactive oxygen species that can initiate oxidative damage and redox signaling (zyrina2017mitochondrialsuperoxidedismutase pages 7-9).
The core SOD reaction is the dismutation of superoxide:
2 O2•− + 2 H+ → H2O2 + O2.
For yeast Sod2p, this is described directly as conversion of superoxide to H2O2 and oxygen (gupta2023mitochondrialsuperoxidedismutase pages 1-2), and is also summarized in MnSOD-focused reviews (grujicic2025manganesesuperoxidedismutase pages 1-3, grujicic2024mnsodmimeticsin pages 2-4). Substrate specificity is thus for the superoxide radical/anionic species, not ROS in general.
Sod2p is a metalloenzyme requiring manganese at the active site; Mn cycles between Mn2+/Mn3+ redox states during catalysis (grujicic2025manganesesuperoxidedismutase pages 1-3). MnSOD structural/mechanistic summaries describe canonical coordination by histidines/aspartate plus a water ligand (His26/His74/His163/Asp159/WAT1 in a common numbering scheme) and outline the Mn redox cycle producing H2O2 from superoxide (grujicic2025manganesesuperoxidedismutase pages 3-5).
MnSOD is nuclear-encoded and imported into the mitochondrial matrix, where it is described as the only mitochondrial SOD (grujicic2025manganesesuperoxidedismutase pages 1-3). In yeast, Sod2 is explicitly called “the mitochondrial matrix protein Sod2” (gupta2023mitochondrialsuperoxidedismutase pages 1-2).
Sod2p’s primary biochemical role is to eliminate mitochondrial superoxide radicals by converting them to H2O2 and O2 (gupta2023mitochondrialsuperoxidedismutase pages 1-2). This supports mitochondrial redox balance and limits downstream formation of more reactive oxidants derived from superoxide chemistry (gupta2023mitochondrialsuperoxidedismutase pages 11-12).
In a 2023 study, Sod2-RFP was reported as distributed throughout mitochondrial networks and showed minimal overlap with DAPI-stained nuclei (only 1.6% ± 0.5 of cells) during oxidative stress conditions, arguing against stress-induced nuclear relocalization and supporting persistent mitochondrial localization (gupta2023mitochondrialsuperoxidedismutase pages 4-5). Corresponding figure evidence is shown in the cropped images (gupta2023mitochondrialsuperoxidedismutase media f9107816).
Sod2p protects cells against oxygen toxicity and oxidative stress and limits oxidative damage (stepien2020impactofcurcumin pages 1-3, zyrina2017mitochondrialsuperoxidedismutase pages 7-9). Loss of Sod2 is associated with reduced resistance to pro-oxidants such as menadione and paraquat in ethanol-tolerance studies (zyrina2017mitochondrialsuperoxidedismutase pages 7-9).
A key mechanistic model in yeast is that Sod2p-generated H2O2 serves as a signaling molecule that activates/relocalizes the transcription factor Yap1p under ethanol stress (zyrina2017mitochondrialsuperoxidedismutase pages 11-13, zyrina2017mitochondrialsuperoxidedismutase pages 7-9). Ethanol (12–16%) induces Yap1 relocalization, and repression of SOD2 prevents this relocalization while H2O2 can still activate Yap1 in Sod2-repressed cells—supporting the role of Sod2-produced H2O2 specifically in ethanol-triggered signaling (zyrina2017mitochondrialsuperoxidedismutase pages 7-9).
A 2023 GENETICS study identified a role for Sod2 in suppressing nuclear chromosomal rearrangements under paraquat-induced oxidative stress, particularly in genetic interaction with the RecQ helicase Sgs1 (gupta2023mitochondrialsuperoxidedismutase pages 1-2). The authors propose that mitochondrial superoxide/derived oxidants can leak/redox-signal to the nucleus and generate oxidative DNA lesions; in PQ-treated sod2Δ cells, genome instability is promoted by HR/TLS factors including Rad51, Pol32, and the Rev1/Pol ζ mutasome (gupta2023mitochondrialsuperoxidedismutase pages 11-12).
The same 2023 study quantified mitochondrial morphology categories and showed that sod2Δ cells exhibited increased mitochondrial fragmentation (41% ± 5.8 fragmented), while sgs1Δ cells showed increased branching (47% ± 1.7 branched); the double mutant resembled sgs1Δ more than sod2Δ (branched 32% ± 5.8; fragmented 8% ± 1.7) (gupta2023mitochondrialsuperoxidedismutase pages 4-5). Figure evidence for these morphology categories and quantification is shown in the cropped figure set (gupta2023mitochondrialsuperoxidedismutase media f9107816).
Gupta et al. (GENETICS; published Aug 2023; https://doi.org/10.1093/genetics/iyad147) provided multiple lines of evidence that Sod2 protects against nuclear genome instability under oxidative stress without major relocalization to nuclei, including:
- Sod2-RFP localization primarily to mitochondria with only 1.6% ± 0.5 nuclear overlap (gupta2023mitochondrialsuperoxidedismutase pages 4-5)
- Quantified mitochondrial morphology shifts in sod2Δ and sgs1Δ (above) (gupta2023mitochondrialsuperoxidedismutase pages 4-5)
- Mechanistic genetic dependencies on HR and TLS pathways for rearrangements in oxidatively stressed sod2Δ cells (gupta2023mitochondrialsuperoxidedismutase pages 11-12)
Święciło et al. (Scientific Reports; published Sep 2024; https://doi.org/10.1038/s41598-024-72400-4) explicitly tested Δsod2 strains under short-term and long-term DMSO exposure and reported concentration-dependent outcomes:
- In 1-hour exposures, Δsod2 viability did not significantly decrease until 20% (v/v) DMSO, where viability dropped by ~36.3% versus control (swieciło2024theeffectof pages 4-5).
- In long-term exposure spot assays, 4% DMSO completely inhibited growth of both Δsod1 and Δsod2 mutants (swieciło2024theeffectof pages 5-6).
- Superoxide levels increased with DMSO concentration and increases were stronger in sod mutants, consistent with DMSO provoking oxidative stress; oxygen limitation (hypoxia/anoxia) improved growth under DMSO, consistent with a respiration/ROS contribution (swieciło2024theeffectof pages 6-7, swieciło2024theeffectof pages 7-8).
Hsu et al. (FEMS Yeast Research; published Jan 2024; https://doi.org/10.1093/femsyr/foae005) reported that ribosomal protein gene mutants exhibit increased oxidative stress (higher H2O2) and increased antioxidant enzyme activity at stationary phase, with catalase especially elevated, and show translational reprogramming of oxidative-stress transcripts (hsu2024mutationsofribosomal pages 1-2, hsu2024mutationsofribosomal pages 7-9). While the accessible excerpts did not provide Sod2-specific quantitative changes, the study provides authoritative recent context that yeast oxidative-stress defenses are co-regulated at transcriptional and translational levels during stress and stationary phase (hsu2024mutationsofribosomal pages 7-9).
A direct application-relevant implication is ethanol tolerance. Zyrina et al. (Applied and Environmental Microbiology; published Feb 2017; https://doi.org/10.1128/AEM.02759-16) explicitly state their findings “could be useful for the improvements of ethanol tolerance in the industrial strains,” based on a proposed Sod2p–Yap1p signaling module and its interaction with retrograde signaling (zyrina2017mitochondrialsuperoxidedismutase pages 11-13). Specific experimentally supported levers include:
- Mild H2O2 pretreatment (0.05 mM) to restore ethanol tolerance in SOD2-repressed cells (zyrina2017mitochondrialsuperoxidedismutase pages 11-13)
- Genetic or signaling interventions affecting retrograde signaling (e.g., activation by 2 mM methionine-sulfoximine or deletion of the negative regulator MKS1) that restore/improve ethanol resistance in SOD2-repressed contexts (zyrina2017mitochondrialsuperoxidedismutase pages 9-11)
These are laboratory demonstrations rather than deployed industrial protocols, but they map directly onto strain engineering and process conditioning concepts.
A 2025 engineering-focused review (Feng et al.; Chem & Bio Engineering; published May 2025; https://doi.org/10.1021/cbe.5c00021) provides expert recommendations relevant to Sod2-centered engineering:
- Prefer dynamic, stress-responsive expression of antioxidant genes (to reduce metabolic burden of constitutive overexpression) (feng2025mechanismsandstrategies pages 7-9).
- Consider pathway-level modulation (e.g., TOR downregulation), which can be accompanied by Sod2p upregulation and reduced ROS during stationary phase (feng2025mechanismsandstrategies pages 7-9).
Although this review is outside 2023–2024, it synthesizes engineering practice and cautions that upstream pathway manipulation can have growth-phase-dependent effects on mitochondrial ROS (feng2025mechanismsandstrategies pages 7-9).
MnSOD reviews emphasize that MnSOD is localized to the mitochondrial matrix, uses manganese redox cycling, and sits at a key control point where mitochondrial superoxide is converted into H2O2, a species that is both less reactive than superoxide and capable of acting in redox signaling (grujicic2025manganesesuperoxidedismutase pages 1-3, grujicic2025manganesesuperoxidedismutase pages 3-5). This conceptual framing supports interpretation of yeast results where Sod2-derived H2O2 functions as an upstream signal (e.g., Yap1 activation) (zyrina2017mitochondrialsuperoxidedismutase pages 11-13).
Zyrina et al. explicitly argue that Sod2 has a signaling role in ethanol tolerance in addition to antioxidant protection, proposing a mitochondria-to-nucleus module (Sod2→H2O2→Yap1) that interacts with retrograde signaling (zyrina2017mitochondrialsuperoxidedismutase pages 11-13). This is an expert mechanistic interpretation grounded in genetic and physiological epistasis experiments (zyrina2017mitochondrialsuperoxidedismutase pages 7-9).
The following table consolidates the functional annotation and key evidence into a compact map.
| Aspect | Summary | Evidence/Citations |
|---|---|---|
| Identity / orthology verification | Verified target: SOD2 / YHR008C / UniProt P00447 in Saccharomyces cerevisiae S288c encodes the mitochondrial manganese superoxide dismutase (MnSOD), distinct from cytosolic SOD1. Literature cited here explicitly describes yeast Sod2 as the mitochondrial/matrix MnSOD, matching the UniProt description and Fe/Mn SOD family assignment. | Yeast Sod2 is explicitly described as mitochondrial matrix MnSOD, contrasted with Sod1 in cytosol/intermembrane space (gupta2023mitochondrialsuperoxidedismutase pages 1-2, maslanka2020linkagebetweencarbon pages 1-3, stepien2020impactofcurcumin pages 1-3) |
| Enzymatic reaction / substrate | Primary function is dismutation of superoxide radical generated largely by mitochondrial respiration: 2 O2•− + 2 H+ -> H2O2 + O2. Substrate specificity is the superoxide anion/radical rather than broader ROS. | Explicit statements that Sod2/MnSOD converts superoxide to H2O2 and O2; superoxide is the relevant substrate (gupta2023mitochondrialsuperoxidedismutase pages 1-2, grujicic2025manganesesuperoxidedismutase pages 1-3, grujicic2024mnsodmimeticsin pages 2-4) |
| Cofactor / active site | Sod2 is a manganese-dependent metalloenzyme; Mn cycles between Mn2+/Mn3+ during catalysis. Reviews describe the canonical MnSOD coordination sphere (His26, His74, His163, Asp159, water ligand), consistent with Fe/Mn SOD family chemistry. | Mn requirement and Mn2+/Mn3+ redox cycling stated directly; active-site coordination detailed in MnSOD review (grujicic2025manganesesuperoxidedismutase pages 1-3, grujicic2025manganesesuperoxidedismutase pages 3-5) |
| Subcellular localization | Sod2 is a nuclear-encoded precursor imported into the mitochondrial matrix. In yeast imaging, Sod2-RFP is distributed throughout mitochondrial networks and does not substantially relocalize to the nucleus during oxidative stress. | Matrix localization stated directly; microscopy shows mitochondrial distribution with only 1.6% ± 0.5 cells showing overlap with DAPI-stained nuclei (gupta2023mitochondrialsuperoxidedismutase pages 1-2, grujicic2025manganesesuperoxidedismutase pages 1-3, gupta2023mitochondrialsuperoxidedismutase pages 4-5, gupta2023mitochondrialsuperoxidedismutase media f9107816) |
| Biological role: oxidative stress defense | Canonical role is detoxification of mitochondrial superoxide to preserve mitochondrial redox homeostasis and protect against oxygen/oxidative toxicity. Loss of Sod2 increases sensitivity to ROS-generating agents and contributes to mitochondrial dysfunction. | General antioxidant role and protection from oxygen toxicity/oxidative stress described in yeast-focused and general MnSOD sources (gupta2023mitochondrialsuperoxidedismutase pages 1-2, stepien2020impactofcurcumin pages 1-3, zyrina2017mitochondrialsuperoxidedismutase pages 7-9) |
| Biological role: ethanol tolerance signaling via Yap1 | Beyond detoxification, Sod2 has a signaling role: Sod2-generated H2O2 helps activate/relocalize the redox transcription factor Yap1 during ethanol stress. Genetic epistasis supports a Sod2-Yap1 module, and 0.05 mM H2O2 pretreatment can rescue ethanol tolerance when SOD2 is repressed. | Ethanol-stress signaling, Yap1 relocalization dependence on Sod2, and H2O2 rescue are reported directly (zyrina2017mitochondrialsuperoxidedismutase pages 11-13, zyrina2017mitochondrialsuperoxidedismutase pages 7-9, zyrina2017mitochondrialsuperoxidedismutase pages 1-3, zyrina2017mitochondrialsuperoxidedismutase pages 9-11) |
| Biological role: genome stability under oxidative stress | A 2023 study showed Sod2 suppresses nuclear genome instability during oxidative stress, especially in the context of sgs1Δ. Mechanistically, mitochondrial superoxide/derived oxidants can promote DNA lesions; in sod2Δ, paraquat-induced rearrangements depend on Rad51, Pol32, Rev1/Pol zeta pathways. | 2023 Genetics study links mitochondrial Sod2 to suppression of nuclear chromosomal rearrangements under oxidative stress (gupta2023mitochondrialsuperoxidedismutase pages 11-12, gupta2023mitochondrialsuperoxidedismutase pages 1-2) |
| Biological role: mitochondrial morphology / homeostasis | Sod2 contributes to normal mitochondrial network architecture. In morphology scoring, sod2Δ cells were enriched for fragmented mitochondria, whereas sgs1Δ showed excess branching; Sod2 therefore intersects redox control with mitochondrial structural homeostasis. | Quantified morphology phenotypes from 2023 paper and accompanying figure summary (gupta2023mitochondrialsuperoxidedismutase pages 4-5, gupta2023mitochondrialsuperoxidedismutase media f9107816) |
| Mutant phenotypes with quantitative data | Reported quantitative phenotypes include: sod2Δ fragmented mitochondria = 41% ± 5.8; sgs1Δ branched mitochondria = 47% ± 1.7; sgs1Δ sod2Δ branched = 32% ± 5.8, fragmented = 8% ± 1.7; nuclear colocalization of Sod2-RFP with DAPI only 1.6% ± 0.5. For stress phenotypes, SOD2 repression decreases survival under 12-18% ethanol and deletion strongly decreases resistance to 20% ethanol; SOD2 repression also lowers resistance to menadione and paraquat. | Quantitative morphology and localization values from Gupta et al. 2023; ethanol/prooxidant conditions from Zyrina et al. 2017 (gupta2023mitochondrialsuperoxidedismutase pages 4-5, zyrina2017mitochondrialsuperoxidedismutase pages 7-9, zyrina2017mitochondrialsuperoxidedismutase pages 1-3, gupta2023mitochondrialsuperoxidedismutase media f9107816) |
| Applications / engineering implications | SOD2 is relevant to industrial stress tolerance engineering because mitochondrial redox control and H2O2 signaling shape ethanol resistance. Proposed/implicit strategies include tuning SOD2, YAP1, and retrograde signaling, using stress-responsive promoters, or modulating TOR to increase Sod2-associated oxidative stress resistance. Reviews note broader antioxidant-enzyme engineering as a route to improve fermentation robustness. | Direct industrial relevance discussed for ethanol tolerance; 2025 review highlights engineering oxidative-stress resistance and notes TOR downregulation can be accompanied by Sod2p upregulation (zyrina2017mitochondrialsuperoxidedismutase pages 11-13, zyrina2017mitochondrialsuperoxidedismutase pages 1-3, feng2025mechanismsandstrategies pages 7-9) |
Table: This table summarizes verified identity, core biochemical function, localization, pathway roles, mutant phenotypes, and engineering relevance for Saccharomyces cerevisiae SOD2/YHR008C. It is useful as a compact evidence map linking classic function to recent 2023 findings on genome stability and mitochondrial morphology.
Cropped figures from Gupta et al. (2023) provide direct visual support for (i) Sod2-RFP mitochondrial localization vs DAPI and (ii) mitochondrial morphology categories and their quantification across genotypes/stresses (gupta2023mitochondrialsuperoxidedismutase media f9107816).
References
(gupta2023mitochondrialsuperoxidedismutase pages 1-2): Sonia Vidushi Gupta, Lillian Campos, and Kristina Hildegard Schmidt. Mitochondrial superoxide dismutase sod2 suppresses nuclear genome instability during oxidative stress. GENETICS, Aug 2023. URL: https://doi.org/10.1093/genetics/iyad147, doi:10.1093/genetics/iyad147. This article has 20 citations and is from a domain leading peer-reviewed journal.
(grujicic2025manganesesuperoxidedismutase pages 1-3): Jovan Grujicic and Antiño R. Allen. Manganese superoxide dismutase: structure, function, and implications in human disease. Antioxidants, 14:848, Jul 2025. URL: https://doi.org/10.3390/antiox14070848, doi:10.3390/antiox14070848. This article has 34 citations.
(zyrina2017mitochondrialsuperoxidedismutase pages 11-13): Anna N. Zyrina, Ekaterina A. Smirnova, Olga V. Markova, Fedor F. Severin, and Dmitry A. Knorre. Mitochondrial superoxide dismutase and yap1p act as a signaling module contributing to ethanol tolerance of the yeast saccharomyces cerevisiae. Applied and Environmental Microbiology, Feb 2017. URL: https://doi.org/10.1128/aem.02759-16, doi:10.1128/aem.02759-16. This article has 39 citations and is from a peer-reviewed journal.
(maslanka2020linkagebetweencarbon pages 1-3): Roman Maslanka, Renata Zadrag-Tecza, and Magdalena Kwolek-Mirek. Linkage between carbon metabolism, redox status and cellular physiology in the yeast saccharomyces cerevisiae devoid of sod1 or sod2 gene. Genes, 11:780, Jul 2020. URL: https://doi.org/10.3390/genes11070780, doi:10.3390/genes11070780. This article has 46 citations.
(stepien2020impactofcurcumin pages 1-3): Karolina Stępień, Dominik Wojdyła, Katarzyna Nowak, and Mateusz Mołoń. Impact of curcumin on replicative and chronological aging in the saccharomyces cerevisiae yeast. Biogerontology, 21:109-123, Oct 2020. URL: https://doi.org/10.1007/s10522-019-09846-x, doi:10.1007/s10522-019-09846-x. This article has 58 citations and is from a peer-reviewed journal.
(zyrina2017mitochondrialsuperoxidedismutase pages 7-9): Anna N. Zyrina, Ekaterina A. Smirnova, Olga V. Markova, Fedor F. Severin, and Dmitry A. Knorre. Mitochondrial superoxide dismutase and yap1p act as a signaling module contributing to ethanol tolerance of the yeast saccharomyces cerevisiae. Applied and Environmental Microbiology, Feb 2017. URL: https://doi.org/10.1128/aem.02759-16, doi:10.1128/aem.02759-16. This article has 39 citations and is from a peer-reviewed journal.
(grujicic2024mnsodmimeticsin pages 2-4): Jovan Grujicic and Antiño R. Allen. Mnsod mimetics in therapy: exploring their role in combating oxidative stress-related diseases. Antioxidants, 13:1444, Nov 2024. URL: https://doi.org/10.3390/antiox13121444, doi:10.3390/antiox13121444. This article has 21 citations.
(grujicic2025manganesesuperoxidedismutase pages 3-5): Jovan Grujicic and Antiño R. Allen. Manganese superoxide dismutase: structure, function, and implications in human disease. Antioxidants, 14:848, Jul 2025. URL: https://doi.org/10.3390/antiox14070848, doi:10.3390/antiox14070848. This article has 34 citations.
(gupta2023mitochondrialsuperoxidedismutase pages 11-12): Sonia Vidushi Gupta, Lillian Campos, and Kristina Hildegard Schmidt. Mitochondrial superoxide dismutase sod2 suppresses nuclear genome instability during oxidative stress. GENETICS, Aug 2023. URL: https://doi.org/10.1093/genetics/iyad147, doi:10.1093/genetics/iyad147. This article has 20 citations and is from a domain leading peer-reviewed journal.
(gupta2023mitochondrialsuperoxidedismutase pages 4-5): Sonia Vidushi Gupta, Lillian Campos, and Kristina Hildegard Schmidt. Mitochondrial superoxide dismutase sod2 suppresses nuclear genome instability during oxidative stress. GENETICS, Aug 2023. URL: https://doi.org/10.1093/genetics/iyad147, doi:10.1093/genetics/iyad147. This article has 20 citations and is from a domain leading peer-reviewed journal.
(gupta2023mitochondrialsuperoxidedismutase media f9107816): Sonia Vidushi Gupta, Lillian Campos, and Kristina Hildegard Schmidt. Mitochondrial superoxide dismutase sod2 suppresses nuclear genome instability during oxidative stress. GENETICS, Aug 2023. URL: https://doi.org/10.1093/genetics/iyad147, doi:10.1093/genetics/iyad147. This article has 20 citations and is from a domain leading peer-reviewed journal.
(swieciło2024theeffectof pages 4-5): Agata Święciło, Ewa Januś, Anna Krzepiłko, and Monika Skowrońska. The effect of dmso on saccharomyces cerevisiae yeast with different energy metabolism and antioxidant status. Scientific Reports, Sep 2024. URL: https://doi.org/10.1038/s41598-024-72400-4, doi:10.1038/s41598-024-72400-4. This article has 8 citations and is from a peer-reviewed journal.
(swieciło2024theeffectof pages 5-6): Agata Święciło, Ewa Januś, Anna Krzepiłko, and Monika Skowrońska. The effect of dmso on saccharomyces cerevisiae yeast with different energy metabolism and antioxidant status. Scientific Reports, Sep 2024. URL: https://doi.org/10.1038/s41598-024-72400-4, doi:10.1038/s41598-024-72400-4. This article has 8 citations and is from a peer-reviewed journal.
(swieciło2024theeffectof pages 6-7): Agata Święciło, Ewa Januś, Anna Krzepiłko, and Monika Skowrońska. The effect of dmso on saccharomyces cerevisiae yeast with different energy metabolism and antioxidant status. Scientific Reports, Sep 2024. URL: https://doi.org/10.1038/s41598-024-72400-4, doi:10.1038/s41598-024-72400-4. This article has 8 citations and is from a peer-reviewed journal.
(swieciło2024theeffectof pages 7-8): Agata Święciło, Ewa Januś, Anna Krzepiłko, and Monika Skowrońska. The effect of dmso on saccharomyces cerevisiae yeast with different energy metabolism and antioxidant status. Scientific Reports, Sep 2024. URL: https://doi.org/10.1038/s41598-024-72400-4, doi:10.1038/s41598-024-72400-4. This article has 8 citations and is from a peer-reviewed journal.
(hsu2024mutationsofribosomal pages 1-2): Ching-Hsiang Hsu, Ching-Yu Liu, and Kai-Yin Lo. Mutations of ribosomal protein genes induce overexpression of catalase in saccharomyces cerevisiae. FEMS Yeast Research, Jan 2024. URL: https://doi.org/10.1093/femsyr/foae005, doi:10.1093/femsyr/foae005. This article has 5 citations and is from a peer-reviewed journal.
(hsu2024mutationsofribosomal pages 7-9): Ching-Hsiang Hsu, Ching-Yu Liu, and Kai-Yin Lo. Mutations of ribosomal protein genes induce overexpression of catalase in saccharomyces cerevisiae. FEMS Yeast Research, Jan 2024. URL: https://doi.org/10.1093/femsyr/foae005, doi:10.1093/femsyr/foae005. This article has 5 citations and is from a peer-reviewed journal.
(zyrina2017mitochondrialsuperoxidedismutase pages 9-11): Anna N. Zyrina, Ekaterina A. Smirnova, Olga V. Markova, Fedor F. Severin, and Dmitry A. Knorre. Mitochondrial superoxide dismutase and yap1p act as a signaling module contributing to ethanol tolerance of the yeast saccharomyces cerevisiae. Applied and Environmental Microbiology, Feb 2017. URL: https://doi.org/10.1128/aem.02759-16, doi:10.1128/aem.02759-16. This article has 39 citations and is from a peer-reviewed journal.
(feng2025mechanismsandstrategies pages 7-9): Taotao Feng, Hongwei Yu, and Lidan Ye. Mechanisms and strategies for engineering oxidative stress resistance in saccharomyces cerevisiae. Chem & Bio Engineering, 2:409-422, May 2025. URL: https://doi.org/10.1021/cbe.5c00021, doi:10.1021/cbe.5c00021. This article has 15 citations.
(zyrina2017mitochondrialsuperoxidedismutase pages 1-3): Anna N. Zyrina, Ekaterina A. Smirnova, Olga V. Markova, Fedor F. Severin, and Dmitry A. Knorre. Mitochondrial superoxide dismutase and yap1p act as a signaling module contributing to ethanol tolerance of the yeast saccharomyces cerevisiae. Applied and Environmental Microbiology, Feb 2017. URL: https://doi.org/10.1128/aem.02759-16, doi:10.1128/aem.02759-16. This article has 39 citations and is from a peer-reviewed journal.
id: P00447
gene_symbol: SOD2
aliases:
- YHR008C
product_type: PROTEIN
status: COMPLETE
taxon:
id: NCBITaxon:559292
label: Saccharomyces cerevisiae
description: Manganese-dependent superoxide dismutase localized to the
mitochondrial matrix. SOD2 catalyzes the dismutation of superoxide radicals
(O2•−) to hydrogen peroxide and molecular oxygen, serving as a critical
antioxidant defense mechanism against reactive oxygen species generated during
mitochondrial respiration. The enzyme contains one manganese ion per subunit
and functions as a homotetramer.
existing_annotations:
- term:
id: GO:0005739
label: mitochondrion
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: IBA annotation for mitochondrial localization based on phylogenetic
inference across orthologous SOD2 proteins. Well-supported by multiple
direct experimental observations confirming mitochondrial matrix
localization.
action: ACCEPT
reason: SOD2 is a well-established mitochondrial protein. The mitochondrial
localization is supported by extensive evidence including direct
biochemical purification from mitochondria, subcellular fractionation
studies, and the presence of a mitochondrial transit peptide (residues
1-26) that is cleaved upon import. IBA inference from orthologous
sequences is appropriate for this annotation as SOD2 localization is
conserved across eukaryotes.
supported_by:
- reference_id: PMID:238997
supporting_text: "The cyanide-insensitive superoxide dismutase of yeast has
been shown to be localized in the mitochondrial matrix."
- reference_id: PMID:15851472
supporting_text: "Manganese-dependent superoxide dismutase 2 (SOD2) in the mitochondria
plays a key role in protection against oxidative stress."
- term:
id: GO:0004784
label: superoxide dismutase activity
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: IBA annotation for superoxide dismutase catalytic activity,
inferred from orthologous SOD2 proteins. Core molecular function of SOD2
and highly conserved across eukaryotes. This annotation is more specific
and appropriate than broader "oxidoreductase activity" annotations.
action: ACCEPT
reason: >
SOD2's primary molecular function is superoxide dismutase activity. The enzyme
catalyzes conversion of superoxide anion to hydrogen peroxide and oxygen
(EC 1.15.1.1). This is a highly specific and informative functional annotation
representing the core catalytic activity. IBA inference is appropriate given
the high conservation of this enzyme family across eukaryotes and consistent
functional characterization of SOD2 orthologs.
supported_by:
- reference_id: PMID:238997
supporting_text: "This enzyme has been isolated in good yield from bakers' yeast...This
enzyme has activity comparable to that of other previously reported superoxide
dismutases"
- reference_id: PMID:15851472
supporting_text: "Manganese-dependent superoxide dismutase 2 (SOD2) in the mitochondria
plays a key role in protection against oxidative stress"
- reference_id: file:yeast/SOD2/SOD2-deep-research-falcon.md
supporting_text: Falcon literature synthesis supports SOD2 as the mitochondrial manganese superoxide dismutase that detoxifies superoxide generated during respiration.
- reference_id: file:interpro/panther/PTHR11404/PTHR11404-metadata.yaml
supporting_text: PANTHER PTHR11404 identifies SOD2 in the iron/manganese superoxide dismutase family.
- term:
id: GO:0030145
label: manganese ion binding
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: >
IBA annotation for manganese ion binding cofactor requirement. SOD2 requires
manganese for catalytic activity with 1 Mn2+ per subunit. Critical for enzyme
function and essential for distinguishing from cytoplasmic Fe-SOD1.
action: ACCEPT
reason: >
SOD2 is a manganese-dependent superoxide dismutase, distinguishing it from the
iron-dependent SOD1 isoform found in the cytoplasm. The UniProt entry explicitly
states "Binds 1 Mn(2+) ion per subunit" with specific binding residues identified
(positions 52, 107, 194, 198). Manganese insertion is essential during import
into mitochondria and is mechanistically coupled to the mitochondrial import
process. This annotation is more specific and informative than generic "metal
ion
binding" annotations and reflects the specialized cofactor requirement.
supported_by:
- reference_id: PMID:238997
supporting_text: "This enzyme contains 1 atom of manganese per subunit and its
absorption in the visible suggests Mn(III) in the resting enzyme."
- reference_id: PMID:15851472
supporting_text: "We found that a mitochondrial localization is essential...Manganese
insertion is only possible with a newly synthesized polypeptide."
- term:
id: GO:0004784
label: superoxide dismutase activity
evidence_type: IEA
original_reference_id: GO_REF:0000120
review:
summary: >
IEA annotation via InterPro mapping (IPR001189: Mn/Fe superoxide dismutase).
Redundant with IBA and IDA annotations for the same function but from automated
computational mapping. Acceptable but less evidence-rich than experimental data.
action: ACCEPT
reason: >
This IEA annotation derives from InterPro domain mapping, which appropriately
identifies SOD2 as a superoxide dismutase based on conserved protein domains.
While less informative than direct experimental evidence, automated annotations
based on InterPro are generally reliable for well-characterized enzyme families.
The annotation is not contradicted by experimental evidence and supports the
core function identified by IBA and IDA annotations.
supported_by:
- reference_id: GO_REF:0000120
supporting_text: Combined Automated Annotation using Multiple IEA Methods
based on InterPro domain mapping
- term:
id: GO:0005739
label: mitochondrion
evidence_type: IEA
original_reference_id: GO_REF:0000117
review:
summary: >
IEA annotation for mitochondrial localization via ARBA machine learning models.
Represents automated inference from amino acid sequence patterns associated
with
mitochondrial proteins. Redundant with direct experimental evidence.
action: ACCEPT
reason: >
ARBA machine learning models provide evidence for mitochondrial localization
based on sequence patterns trained on experimentally validated mitochondrial
proteins. While less directly informative than experimental evidence, this IEA
annotation is consistent with and supported by extensive experimental data
including direct biochemical purification and subcellular localization studies.
- term:
id: GO:0005759
label: mitochondrial matrix
evidence_type: IEA
original_reference_id: GO_REF:0000044
review:
summary: >
IEA annotation based on UniProtKB subcellular location vocabulary mapping to
"Mitochondrion matrix". More specific than broader "mitochondrion" annotation,
reflecting SOD2's precise subcellular compartment.
action: ACCEPT
reason: >
The annotation correctly identifies the mitochondrial matrix as SOD2's specific
subcellular compartment. This IEA is derived from structured UniProtKB annotation
and is supported by direct experimental evidence. The matrix localization is
essential for SOD2 function in protecting mitochondrial proteins and DNA from
superoxide generated by the electron transport chain. This is more specific
and
informative than the broader "mitochondrion" annotations.
supported_by:
- reference_id: PMID:238997
supporting_text: "The cyanide-insensitive superoxide dismutase of yeast has
been shown to be localized in the mitochondrial matrix."
- term:
id: GO:0006801
label: superoxide metabolic process
evidence_type: IEA
original_reference_id: GO_REF:0000002
review:
summary: >
IEA annotation for involvement in superoxide metabolic process based on InterPro
domain mapping. Reasonable but somewhat redundant with more specific process
annotations like "removal of superoxide radicals".
action: ACCEPT
reason: >
This annotation appropriately captures SOD2's involvement in superoxide metabolism
through the dismutation reaction. However, it is broader than the more specific
functional process "removal of superoxide radicals" (GO:0019430) which more
precisely describes the biological outcome. The annotation is not incorrect
but
represents a higher-level categorization of the more specific process.
- term:
id: GO:0016209
label: antioxidant activity
evidence_type: IEA
original_reference_id: GO_REF:0000043
review:
summary: >
IEA annotation based on UniProtKB keyword mapping (KW-0049: Antioxidant).
Accurate but relatively broad characterization of SOD2's functional role.
action: ACCEPT
reason: >
SOD2 is correctly characterized as having antioxidant activity through its
superoxide dismutase function. While this annotation is less specific than
GO:0004784 (superoxide dismutase activity), it is accurate and captures the
physiological consequence of the enzyme's catalytic activity. Antioxidant
activity represents an appropriate functional categorization for SOD2.
- term:
id: GO:0016491
label: oxidoreductase activity
evidence_type: IEA
original_reference_id: GO_REF:0000043
review:
summary: >
IEA annotation based on UniProtKB keyword mapping (KW-0560: Oxidoreductase).
Correct but very broad categorization of enzymatic function.
action: KEEP_AS_NON_CORE
reason: >
While technically correct that superoxide dismutase is an oxidoreductase enzyme
(catalyzing electron transfer in the dismutation reaction), this annotation
is
overly broad and lacks specificity. The broader "oxidoreductase activity"
encompasses thousands of diverse enzymatic activities and provides minimal
functional information. More specific annotations like "superoxide dismutase
activity" and "antioxidant activity" are far more informative. However, it is
not incorrect, so retaining it as non-core is appropriate to avoid cluttering
the functional annotation space.
- term:
id: GO:0019430
label: removal of superoxide radicals
evidence_type: IEA
original_reference_id: GO_REF:0000108
review:
summary: >
IEA annotation inferred via logical inference from the primary superoxide
dismutase activity annotation. Accurately captures the functional consequence
of SOD2's enzymatic activity.
action: ACCEPT
reason: >
This process annotation appropriately captures the biological function of SOD2.
The enzyme removes/detoxifies superoxide radicals by catalyzing their conversion
to hydrogen peroxide and oxygen. This is the functional outcome of the superoxide
dismutase catalytic activity and is logically inferred from that core function.
The annotation is supported by extensive evidence of SOD2's role in cellular
antioxidant defense.
supported_by:
- reference_id: PMID:3520557
supporting_text: "MnSOD contributes to the natural protection of cells against
oxygen toxicity"
- term:
id: GO:0046872
label: metal ion binding
evidence_type: IEA
original_reference_id: GO_REF:0000120
review:
summary: >
IEA annotation for general metal ion binding based on InterPro domain mapping.
Accurate but very broad and less specific than the manganese-specific annotation.
action: KEEP_AS_NON_CORE
reason: >
SOD2 does bind a metal ion (specifically manganese), making this annotation
technically correct. However, it is overly general and lacks the specificity
that makes GO:0030145 (manganese ion binding) superior. While some genes may
require annotation at this level of generality, SOD2's cofactor requirement
is
specifically and characteristically for manganese rather than other metal ions.
The more specific "manganese ion binding" annotation is far more informative
and should be prioritized. Retaining this as non-core avoids redundancy.
- term:
id: GO:0098869
label: cellular oxidant detoxification
evidence_type: IEA
original_reference_id: GO_REF:0000108
review:
summary: >
IEA annotation for cellular oxidant detoxification, inferred from antioxidant
activity via logical inference. Captures the cellular process consequence of
SOD2's enzymatic function.
action: ACCEPT
reason: >
This process annotation appropriately characterizes SOD2's role in protecting
cells from reactive oxygen species. The enzyme detoxifies superoxide and
contributes to overall cellular antioxidant defense. The annotation is logically
inferred from the antioxidant activity function and is supported by experimental
evidence of SOD2's essential role in protecting cells against oxidative stress,
particularly in mitochondria where high ROS levels are generated.
- term:
id: GO:0005739
label: mitochondrion
evidence_type: HDA
original_reference_id: PMID:24769239
review:
summary: >
HDA annotation from quantitative proteomic study identifying SOD2 in isolated
mitochondria during proteomic survey of mitochondrial proteins under different
growth conditions. Supports mitochondrial localization.
action: ACCEPT
reason: >
This HDA annotation is based on direct detection of SOD2 protein in isolated
mitochondrial fractions using mass spectrometry. Quantitative proteomics provides
strong evidence for protein localization. The study systematically identified
mitochondrial proteins and their relative abundance across different metabolic
conditions. This represents solid experimental evidence for mitochondrial
presence, though less specific than subcellular fractionation at the matrix
level.
supported_by:
- reference_id: PMID:24769239
supporting_text: "Label free quantitative analysis of protein accumulation revealed
significant variation of 176 mitochondrial proteins"
- term:
id: GO:0005739
label: mitochondrion
evidence_type: HDA
original_reference_id: PMID:11914276
review:
summary: >
HDA annotation from proteome-scale high-throughput subcellular localization
study
mapping yeast protein localization. Confirms mitochondrial localization through
immunolocalization-based approach.
action: ACCEPT
reason: >
This study represents the first large-scale proteome localization study in yeast,
using high-throughput immunolocalization of epitope-tagged proteins to determine
subcellular localization. SOD2 was identified among proteins localized to
mitochondria in the GOA HDA record. The locally cached publication text contains
the study abstract and methodology but not the SOD2-specific table entry, so this
review cites the PMID-level method and treats matrix-specific localization as
requiring additional evidence.
supported_by:
- reference_id: PMID:11914276
supporting_text: "By high-throughput immunolocalization of tagged gene products, we have determined the subcellular localization of 2744 yeast proteins."
full_text_unavailable: true
- term:
id: GO:0005739
label: mitochondrion
evidence_type: HDA
original_reference_id: PMID:14576278
review:
summary: >
HDA annotation from comprehensive mass spectrometry-based proteomics of purified
yeast mitochondria. SOD2 identified in mitochondrial proteome catalog.
action: ACCEPT
reason: >
This landmark study identified >750 different proteins from highly purified
yeast
mitochondria using tandem mass spectrometry. SOD2 was identified in this
comprehensive mitochondrial proteome. The study analyzed only mitochondrial
fractions, providing direct evidence for mitochondrial localization. This
represents strong experimental support from a well-cited mitochondrial proteomics
resource.
supported_by:
- reference_id: PMID:14576278
supporting_text: "From >20 million MS spectra, 750 different proteins were identified,
indicating an involvement of mitochondria in numerous cellular processes"
- term:
id: GO:0005739
label: mitochondrion
evidence_type: HDA
original_reference_id: PMID:16823961
review:
summary: >
HDA annotation from advanced proteomics study combining multidimensional
separation techniques to characterize the complete yeast mitochondrial proteome.
action: ACCEPT
reason: >
This study used orthogonal proteomics approaches to achieve the most comprehensive
characterization of the yeast mitochondrial proteome, identifying 851 different
proteins. SOD2 was identified as a mitochondrial protein in this resource. The
use of multiple complementary separation and detection methods increases
confidence in protein identification. This represents high-quality experimental
evidence for mitochondrial localization from a mature proteomics platform.
supported_by:
- reference_id: PMID:16823961
supporting_text: "A total of 851 different proteins (PROMITO dataset) were identified
by use of multidimensional LC-MS/MS"
- term:
id: GO:0004784
label: superoxide dismutase activity
evidence_type: IDA
original_reference_id: PMID:15851472
review:
summary: >
IDA annotation from direct enzymatic assay study characterizing manganese
activation of SOD2 in mitochondria. Demonstrates enzyme activity and essential
cofactor requirement.
action: ACCEPT
reason: >
This IDA annotation is from direct biochemical characterization of SOD2 enzyme
activity in mitochondrial context. The study specifically examined manganese
activation of SOD2, demonstrating the enzyme's superoxide dismutase activity
and its dependence on mitochondrial import for proper cofactor insertion. This
represents strong experimental evidence for the core molecular function.
supported_by:
- reference_id: PMID:15851472
supporting_text: "Manganese-dependent superoxide dismutase 2 (SOD2) in the mitochondria
plays a key role in protection against oxidative stress. Here we probed the
pathway by which SOD2 acquires its manganese catalytic cofactor."
- term:
id: GO:0004784
label: superoxide dismutase activity
evidence_type: IDA
original_reference_id: PMID:238997
review:
summary: >
IDA annotation from the landmark 1975 study that first isolated and characterized
manganese-containing SOD from yeast. Original biochemical characterization of
enzyme activity.
action: ACCEPT
reason: >
This is from the seminal study that first isolated yeast mitochondrial SOD and
demonstrated its superoxide dismutase activity in vitro. The study characterized
the enzyme's molecular weight (96,000 Da tetramer), subunit structure, manganese
content (1 Mn per subunit), and catalytic activity. This represents foundational
experimental evidence for SOD2's molecular function and remains a critical
reference for the enzyme's properties.
supported_by:
- reference_id: PMID:238997
supporting_text: "This enzyme has been isolated in good yield from bakers' yeast...This
enzyme contains 1 atom of manganese per subunit...This enzyme has activity
comparable to that of other previously reported superoxide dismutases"
- term:
id: GO:0005739
label: mitochondrion
evidence_type: IDA
original_reference_id: PMID:15851472
review:
summary: >
IDA annotation from manganese activation study that demonstrated SOD2's
mitochondrial localization is essential for cofactor insertion and activation.
action: ACCEPT
reason: >
The study directly showed that mitochondrial localization of SOD2 is essential
for proper manganese insertion and enzyme activation. Cytosolic versions of
SOD2
remain largely apo (without manganese) unless cells are exposed to toxic manganese
levels. This demonstrates mechanistically that SOD2's mitochondrial localization
is not just coincidental but essential for function. The study provides strong
experimental evidence for mitochondrial localization integrated with functional
characterization.
supported_by:
- reference_id: PMID:15851472
supporting_text: "We found that a mitochondrial localization is essential...By
reversibly blocking mitochondrial import in vivo, we noted that newly synthesized
Sod2p can enter mitochondria but not a Sod2p polypeptide that was allowed
to accumulate in the cytosol."
- term:
id: GO:0005759
label: mitochondrial matrix
evidence_type: IDA
original_reference_id: PMID:238997
review:
summary: >
IDA annotation from original characterization study that specifically localized
the enzyme to the mitochondrial matrix compartment. Foundational evidence for
subcellular compartmentalization.
action: ACCEPT
reason: >
The seminal 1975 study explicitly localized the cyanide-insensitive (manganese)
superoxide dismutase to the mitochondrial matrix, the innermost mitochondrial
compartment where the electron transport chain generates superoxide and where
SOD2 provides essential antioxidant protection. This specific subcellular
localization is more informative than broader mitochondrion annotations and
accurately reflects the enzyme's functional compartment. This remains the gold
standard evidence for matrix localization.
supported_by:
- reference_id: PMID:238997
supporting_text: "The cyanide-insensitive superoxide dismutase of yeast has
been shown to be localized in the mitochondrial matrix."
- term:
id: GO:0072593
label: reactive oxygen species metabolic process
evidence_type: IMP
original_reference_id: PMID:3520557
review:
summary: >
IMP annotation from genetic knockout study demonstrating that SOD2 is essential
for cellular protection against oxygen-induced ROS toxicity. Establishes
biological role in ROS metabolism.
action: ACCEPT
reason: >
This IMP annotation is from a landmark genetic study that created a SOD2-null
mutant and demonstrated its hypersensitivity to oxygen. The mutant lacked
cyanide-insensitive SOD activity and exhibited growth inhibition in
oxygen-containing atmospheres, providing direct genetic evidence that SOD2
contributes to cellular defense against oxygen toxicity through ROS metabolism.
This represents the strongest type of biological process evidence showing that
loss of protein function impairs the process.
supported_by:
- reference_id: PMID:3520557
supporting_text: "In the absence of oxygen, the mutant grew as rapidly as the
wild-type parent. However, increasing concentrations of oxygen led to a progressive
inhibition of growth. The properties of this mutant provide direct evidence
that MnSOD contributes to the natural protection of cells against oxygen toxicity."
core_functions:
- molecular_function:
id: GO:0004784
label: superoxide dismutase activity
description: >
Superoxide dismutase activity is the core molecular function of SOD2. The enzyme
catalyzes the highly specific reaction: 2 O2•− + 2 H+ → H2O2 + O2 (EC 1.15.1.1).
Direct biochemical characterization (PMID:238997, PMID:15851472) demonstrates
this catalytic activity. The enzyme requires manganese cofactor (1 Mn2+ per
subunit) which is specifically inserted during mitochondrial import.
directly_involved_in:
- id: GO:0072593
label: reactive oxygen species metabolic process
locations:
- id: GO:0005759
label: mitochondrial matrix
supported_by:
- reference_id: PMID:238997
supporting_text: "This enzyme contains 1 atom of manganese per subunit and its
absorption in the visible suggests Mn(III) in the resting enzyme"
- reference_id: PMID:15851472
supporting_text: "Manganese-dependent superoxide dismutase 2 (SOD2) in the mitochondria
plays a key role in protection against oxidative stress."
- reference_id: file:yeast/SOD2/SOD2-deep-research-falcon.md
supporting_text: Falcon literature synthesis supports SOD2 as the core mitochondrial Mn-dependent superoxide dismutase.
- reference_id: file:interpro/panther/PTHR11404/PTHR11404-metadata.yaml
supporting_text: PANTHER family PTHR11404 groups SOD2 with iron/manganese superoxide dismutases.
proposed_new_terms: []
suggested_questions:
- question: >
What role does SOD2 phosphorylation play in regulating its activity or
localization?
- question: >
Are there condition-specific changes in SOD2 expression or activity in response
to metabolic state?
- question: >
Does SOD2 interact with other mitochondrial proteins to form a larger
antioxidant defense complex?
suggested_experiments:
- description: >
Detailed kinetic analysis of SOD2 with various superoxide concentrations and pH
conditions to establish optimal activity parameters in vivo
- description: >
Investigation of SOD2 regulation by reactive oxygen species or other cellular
signals that might modulate its expression
- description: >
Analysis of the relationship between SOD2 activity and cellular aging or
replicative lifespan in yeast
references:
- id: GO_REF:0000002
title: Gene Ontology annotation through association of InterPro records with
GO terms
findings: []
- id: GO_REF:0000033
title: Annotation inferences using phylogenetic trees
findings: []
- id: GO_REF:0000043
title: Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
findings: []
- id: GO_REF:0000044
title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular
Location vocabulary mapping, accompanied by conservative changes to GO terms
applied by UniProt
findings: []
- id: GO_REF:0000108
title: Automatic assignment of GO terms using logical inference, based on on
inter-ontology links
findings: []
- id: GO_REF:0000117
title: Electronic Gene Ontology annotations created by ARBA machine learning
models
findings: []
- id: GO_REF:0000120
title: Combined Automated Annotation using Multiple IEA Methods
findings: []
- id: PMID:11914276
title: Subcellular localization of the yeast proteome.
findings: []
- id: PMID:14576278
title: The proteome of Saccharomyces cerevisiae mitochondria.
findings: []
- id: PMID:15851472
title: Manganese activation of superoxide dismutase 2 in the mitochondria of
Saccharomyces cerevisiae.
findings: []
- id: PMID:16823961
title: 'Toward the complete yeast mitochondrial proteome: multidimensional separation
techniques for mitochondrial proteomics.'
findings: []
- id: PMID:238997
title: Isolation and characterization of a manganese-containing superoxide
dismutase from yeast.
findings: []
- id: PMID:24769239
title: Quantitative variations of the mitochondrial proteome and
phosphoproteome during fermentative and respiratory growth in Saccharomyces
cerevisiae.
findings: []
- id: PMID:3520557
title: A yeast mutant lacking mitochondrial manganese-superoxide dismutase is
hypersensitive to oxygen.
findings: []
- id: file:yeast/SOD2/SOD2-deep-research-falcon.md
title: Falcon deep research synthesis for SOD2
findings: []
- id: file:interpro/panther/PTHR11404/PTHR11404-metadata.yaml
title: PANTHER family PTHR11404 iron/manganese superoxide dismutase metadata
findings: []