cta1 encodes the only catalase of Schizosaccharomyces pombe, a monofunctional heme catalase (EC 1.11.1.6) that dismutates hydrogen peroxide to water and dioxygen. Deletion abolishes cellular catalase activity and makes cells hypersensitive to high concentrations of exogenous hydrogen peroxide, and overexpression increases peroxide resistance; catalase activity is induced by osmotic stress and, via Pap1, in cells lacking thioredoxin reductase. Catalase is dispensable for normal aerobic growth, where the peroxiredoxin Tpx1 controls low steady-state peroxide levels, and acts as the second barrier when peroxide levels rise. Unlike budding yeast, which has a peroxisomal (Cta1) and a cytosolic (Ctt1) catalase, S. pombe has a single catalase gene; its C-terminus lacks the canonical PTS1 of S. cerevisiae Cta1, and its peroxisomal localization is inferred by similarity.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000302 response to reactive oxygen species | IEA GO_REF:0000117 | TOO GENERAL | Summary: ARBA response to reactive oxygen species. Reason: Broad response term; the direct process is hydrogen peroxide catabolism. Supporting Evidence: PMID:10380645 A catalase gene disruptant completely lacking catalase activity is more sensitive to hydrogen peroxide than the parent strain. |
| GO:0004096 catalase activity | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA catalase activity for the monofunctional heme catalase clade (PTN000157250; S. pombe cta1 is itself among the sources). Reason: Core activity, supported by loss of all catalase activity in the deletion mutant. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt SIMILARITY: Belongs to the catalase family. {ECO:0000305}. PMID:10380645 A catalase gene disruptant completely lacking catalase activity is more sensitive to hydrogen peroxide than the parent strain. |
| GO:0004096 catalase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Combined IEA (ARBA, InterPro catalase signatures, RHEA:20309, EC 1.11.1.6). Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt Reaction=2 H2O2 = O2 + 2 H2O; Xref=Rhea:RHEA:20309, ChEBI:CHEBI:15377, |
| GO:0004096 catalase activity | IMP PMID:10380645 The role of catalase in hydrogen peroxide resistance in fiss... | ACCEPT | Summary: Mutoh et al. 1999: the catalase gene disruptant completely lacks catalase activity. Reason: Core activity; S. pombe has no other catalase. Supporting Evidence: PMID:10380645 A catalase gene disruptant completely lacking catalase activity is more sensitive to hydrogen peroxide than the parent strain. |
| GO:0005737 cytoplasm | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA is_active_in cytoplasm for the catalase clade. Reason: S. pombe has a single catalase that must cover the cytosolic role served by Ctt1 in budding yeast; cytoplasm (which also contains peroxisomes) is the safest location. More accepted here than for S. cerevisiae Cta1, where it was kept as non-core. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt SIMILARITY: Belongs to the catalase family. {ECO:0000305}. PMID:10380645 These results indicate that the catalase of S. pombe plays an important role in resistance to high concentrations of hydrogen peroxide but offers little in the way of protection from the hydrogen peroxide generated in small amounts under normal growth conditions. |
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: PAINT IBA is_active_in mitochondrion whose only experimental donor is S. cerevisiae Cta1, which is co-imported into mitochondria during respiratory growth. Reason: No S. pombe evidence for a mitochondrial catalase pool; the node placement is not contradicted, so retained as non-core rather than removed. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt SIMILARITY: Belongs to the catalase family. {ECO:0000305}. |
| GO:0005759 mitochondrial matrix | ISO GO_REF:0000024 | KEEP AS NON CORE | Summary: ISO is_active_in mitochondrial matrix from S. cerevisiae Cta1 (SGD:S000002664), which is co-imported into mitochondria under respiratory growth. Reason: Not shown for S. pombe catalase; retained as a non-core orthology inference. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt SIMILARITY: Belongs to the catalase family. {ECO:0000305}. |
| GO:0005777 peroxisome | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: PAINT IBA is_active_in peroxisome (PTN000157252, donors animal catalases and S. cerevisiae Cta1). Reason: Plausible, as S. pombe has peroxisomes, but S. pombe cta1 lacks the C-terminal PTS1 of S. cerevisiae Cta1 and no S. pombe peroxisomal localization is in the cached literature. Kept as non-core rather than accepted as the principal location. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt SUBCELLULAR LOCATION: Peroxisome matrix {ECO:0000250|UniProtKB:P15202}. |
| GO:0005782 peroxisomal matrix | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: UniProt subcellular-location mapping of Peroxisome matrix, which UniProt asserts only by similarity to S. cerevisiae Cta1 (P15202). Reason: Inference from a budding-yeast paralog with a PTS1 that S. pombe cta1 lacks; plausible but untested in S. pombe. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt SUBCELLULAR LOCATION: Peroxisome matrix {ECO:0000250|UniProtKB:P15202}. |
| GO:0005782 peroxisomal matrix | ISO GO_REF:0000024 | KEEP AS NON CORE | Summary: ISO is_active_in peroxisomal matrix from S. cerevisiae Cta1 (SGD:S000002664). Reason: Plausible but untested in S. pombe; S. pombe has a single catalase whose main pool may be cytosolic. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt SUBCELLULAR LOCATION: Peroxisome matrix {ECO:0000250|UniProtKB:P15202}. |
| GO:0005782 peroxisomal matrix | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: ISS peroxisomal matrix from S. cerevisiae Cta1 (P15202). Reason: Same assessment as the UniProt-derived row: plausible, not demonstrated for S. pombe, and the S. cerevisiae PTS1 is not conserved. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt SUBCELLULAR LOCATION: Peroxisome matrix {ECO:0000250|UniProtKB:P15202}. |
| GO:0006979 response to oxidative stress | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO response to oxidative stress. Reason: Broad response term. Supporting Evidence: PMID:10380645 A catalase gene disruptant completely lacking catalase activity is more sensitive to hydrogen peroxide than the parent strain. |
| GO:0020037 heme binding | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: PAINT IBA heme binding. Reason: Cofactor binding underlying catalase activity; non-core as in the S. cerevisiae CTA1 review. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt Name=heme; Xref=ChEBI:CHEBI:30413; |
| GO:0020037 heme binding | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: InterPro2GO heme binding. Reason: Cofactor binding; non-core. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt Name=heme; Xref=ChEBI:CHEBI:30413; |
| GO:0042542 response to hydrogen peroxide | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: PAINT IBA response to hydrogen peroxide. Reason: Supported (catalase-null cells are H2O2-hypersensitive and cannot acquire osmotic cross-protection) but a response-level term; the direct process is hydrogen peroxide catabolism. Supporting Evidence: PMID:10380645 A catalase gene disruptant completely lacking catalase activity is more sensitive to hydrogen peroxide than the parent strain. |
| GO:0042744 hydrogen peroxide catabolic process | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA hydrogen peroxide catabolic process. Reason: Core process. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt Reaction=2 H2O2 = O2 + 2 H2O; Xref=Rhea:RHEA:20309, ChEBI:CHEBI:15377, PMID:10380645 A catalase gene disruptant completely lacking catalase activity is more sensitive to hydrogen peroxide than the parent strain. |
| GO:0042744 hydrogen peroxide catabolic process | IEA GO_REF:0000117 | ACCEPT | Summary: ARBA hydrogen peroxide catabolic process. Reason: Core process. Supporting Evidence: file:SCHPO/cta1/cta1-uniprot.txt Reaction=2 H2O2 = O2 + 2 H2O; Xref=Rhea:RHEA:20309, ChEBI:CHEBI:15377, |
| GO:0042744 hydrogen peroxide catabolic process | IMP PMID:10380645 The role of catalase in hydrogen peroxide resistance in fiss... | ACCEPT | Summary: Mutoh et al. 1999: catalase disruption causes H2O2 hypersensitivity and overexpression increases resistance. Supporting Evidence: PMID:10380645 A catalase gene disruptant completely lacking catalase activity is more sensitive to hydrogen peroxide than the parent strain. PMID:10380645 Additionally, transformed cells that overexpress the catalase activity are more resistant to hydrogen peroxide than wildtype cells with normal catalase activity. |
| GO:0042744 hydrogen peroxide catabolic process | IMP PMID:24521463 A genetic approach to study H2O2 scavenging in fission yeast... | ACCEPT | Summary: Paulo et al. 2014: catalase-dependent removal of elevated H2O2 in tpx1 and trr1 mutant backgrounds. Reason: Core process. Supporting Evidence: PMID:24521463 catalase being the next barrier of detoxification when the steady-state levels of peroxides are increased in Ξtpx1 cells. |
| GO:0061692 cellular detoxification of hydrogen peroxide | IMP PMID:24521463 A genetic approach to study H2O2 scavenging in fission yeast... | ACCEPT | Summary: Paulo et al. 2014: catalase is required for suppression of tpx1 aerobic-growth defects by trr1 deletion and is the second barrier of H2O2 detoxification after Tpx1. Reason: Direct genetic evidence for cellular H2O2 detoxification. Supporting Evidence: PMID:24521463 We have investigated this suppression effect, and determined that it depends on the presence of catalase, which is constitutively expressed in Ξtrr1 cells in a transcription factor Pap1-dependent manner. PMID:24521463 catalase being the next barrier of detoxification when the steady-state levels of peroxides are increased in Ξtpx1 cells. |
Loading supporting contentβ¦
Download this section (compressed HTML)Q: Where is S. pombe catalase located: is there a peroxisomal pool despite the absence of the S. cerevisiae-type C-terminal PTS1, and is any catalase imported into mitochondria?
Experiment: Image endogenously tagged Cta1 with peroxisomal (e.g. PTS1-RFP) and mitochondrial markers and fractionate cells grown on glucose and on respiratory carbon sources, comparing wild type with pex mutants.
Loading supporting contentβ¦
Download this section (compressed HTML)