id: P42760 gene_symbol: GSTF6 product_type: PROTEIN status: COMPLETE taxon: id: NCBITaxon:3702 label: Arabidopsis thaliana description: GSTF6 (At1g02930; also called ERD11 or GST1) is a soluble phi-class glutathione S-transferase of Arabidopsis thaliana with a thioredoxin-like N-terminal glutathione-binding domain and an all-helical C-terminal domain. It catalyses conjugation of reduced glutathione to electrophilic substrates, but its activity on the model substrate CDNB is low and its physiological substrates are not firmly established. It has no targeting peptide and is a cytosolic protein. The gene is among the most broadly stress-inducible GSTs in Arabidopsis, responding to dehydration, salicylic acid, ethylene, jasmonate, auxin, oxidative stress, heavy metals, herbicide safeners and pathogens. GSTF6 has been proposed to conjugate glutathione to the activated indole-3-acetonitrile intermediate in camalexin biosynthesis, producing GS-IAN. Supporting this, gstf6 knockouts make modestly less camalexin, overexpression lines make modestly more, and GSTF6 increases GS-IAN formation in yeast. However, higher-order phi GST mutants show no camalexin defect, many other Arabidopsis GSTs support GS-IAN formation, and the activated intermediate can react with glutathione without an enzyme. GSTF6 is therefore best viewed as one of several redundant contributors to this step rather than a dedicated pathway enzyme. It is not part of the P450 camalexin metabolon (the tau-class GSTU4 is recruited there instead) and it does not act as an anthocyanin carrier. existing_annotations: - term: id: GO:0000325 label: plant-type vacuole evidence_type: HDA original_reference_id: PMID:15539469 qualifier: located_in review: summary: GSTF6 was detected by mass spectrometry in a purified vegetative vacuole proteome. action: MARK_AS_OVER_ANNOTATED reason: GSTF6 is a soluble GST with no targeting peptide and is cytosolic. A single detection in an organelle proteome, without targeted validation, most likely reflects carry-over of an abundant stress-induced cytosolic protein. There is no evidence that GSTF6 acts in the vacuole. The deep research specifically warns against transferring the vacuolar-transport role of TT19/GSTF12 to GSTF6. supported_by: - reference_id: PMID:15539469 supporting_text: Total purified vacuolar proteins were then subjected either to multidimensional liquid chromatography/tandem mass spectrometry - reference_id: PMID:21712415 supporting_text: The fourth enzyme, GSTF6, lacks predicted signaling peptides and is therefore most likely cytosolic. - reference_id: file:ARATH/GSTF6/GSTF6-deep-research-falcon.md supporting_text: GSTF6 should therefore not be annotated as the demonstrated TT19-like vacuolar anthocyanin carrier - term: id: GO:0004364 label: glutathione transferase activity evidence_type: IBA original_reference_id: GO_REF:0000033 qualifier: enables supporting_entities: - AGI_LocusCode:AT2G30860 - AGI_LocusCode:AT2G30870 - AGI_LocusCode:AT2G47730 - AGI_LocusCode:AT4G02520 - PANTHER:PTN000136955 - PomBase:SPAC688.04c - SGD:S000003983 - UniProtKB:P04907 - UniProtKB:P0ACA7 - UniProtKB:P12653 - UniProtKB:P46420 - ZFIN:ZDB-GENE-090507-1 review: summary: Phylogenetic inference of glutathione transferase activity across the GST family, including the Arabidopsis phi-class members. action: ACCEPT reason: GSTF6 is a phi-class GST with conserved glutathione-binding residues. Recombinant GSTF6 is soluble and catalyses glutathione conjugation. This is the core molecular function of the protein. The IBA node placement is consistent with the experimental data. supported_by: - reference_id: PMID:12090627 supporting_text: All GSTs except AtGSTF10 formed soluble proteins which catalysed a specific range of glutathione conjugation or glutathione peroxidase activities. - reference_id: PMID:21239642 supporting_text: Arabidopsis GSTF6 expressed in yeast cells catalyzed GSH(IAN) formation. - term: id: GO:0004364 label: glutathione transferase activity evidence_type: IEA original_reference_id: GO_REF:0000120 qualifier: enables supporting_entities: - RHEA:16437 - EC:2.5.1.18 review: summary: Electronic mapping from EC 2.5.1.18 / RHEA:16437 to glutathione transferase activity. action: ACCEPT reason: The mapping is correct. GSTF6 catalyses glutathione conjugation, as shown by experiment. This is the core molecular function. supported_by: - reference_id: PMID:12090627 supporting_text: All GSTs except AtGSTF10 formed soluble proteins which catalysed a specific range of glutathione conjugation or glutathione peroxidase activities. - term: id: GO:0005507 label: copper ion binding evidence_type: HDA original_reference_id: PMID:16526091 qualifier: enables review: summary: GSTF6 was retained on a copper-immobilized metal affinity chromatography (Cu-IMAC) column in a root proteomic survey. action: MARK_AS_OVER_ANNOTATED reason: Retention on an IMAC resin shows that the protein has surface residues (typically His clusters) that can coordinate an immobilized metal. It does not show that the protein binds copper as part of its biological function. GSTF6 is not a known metalloprotein, and no copper site or copper-dependent activity has been described. The annotation records an assay property rather than a molecular function. supported_by: - reference_id: PMID:16526091 supporting_text: we have systematically screened for copper-interacting proteins in Arabidopsis roots via copper-immobilized metal affinity chromatography (Cu-IMAC) - term: id: GO:0005576 label: extracellular region evidence_type: HDA original_reference_id: PMID:28887381 qualifier: located_in review: summary: GSTF6 was detected in a membrane-fraction protein correlation profiling dataset. action: MARK_AS_OVER_ANNOTATED reason: GSTF6 has no signal peptide and is cytosolic. The source study profiled membrane-associated protein complexes after cell fractionation, which is not a suitable assay for assigning an extracellular location. Extracellular action of GSTF6 has not been established. supported_by: - reference_id: PMID:28887381 supporting_text: Over 150 proteins had a complicated localization pattern, and were clearly partitioned between cytosolic and membrane-associated pools. - reference_id: PMID:21712415 supporting_text: The fourth enzyme, GSTF6, lacks predicted signaling peptides and is therefore most likely cytosolic. - term: id: GO:0005737 label: cytoplasm evidence_type: IBA original_reference_id: GO_REF:0000033 qualifier: is_active_in supporting_entities: - AGI_LocusCode:AT1G02920 - AGI_LocusCode:AT1G02930 - AGI_LocusCode:AT2G47730 - AGI_LocusCode:AT4G02520 - AGI_LocusCode:AT5G17220 - PANTHER:PTN000136955 - PomBase:SPAC688.04c - UniProtKB:P0ACA7 review: summary: Phylogenetic inference that phi-class GSTs act in the cytoplasm. action: ACCEPT reason: GSTF6 is a soluble GST without targeting signals. Cytoplasm is correct, and cytosol is the more specific location. supported_by: - reference_id: PMID:21712415 supporting_text: The fourth enzyme, GSTF6, lacks predicted signaling peptides and is therefore most likely cytosolic. - term: id: GO:0005737 label: cytoplasm evidence_type: NAS original_reference_id: PMID:12090627 qualifier: located_in review: summary: Author statement in the Arabidopsis GST family survey that phi GSTs are cytoplasmic. action: ACCEPT reason: This agrees with the absence of targeting peptides and the soluble nature of the recombinant protein. It is consistent with the IBA and the cytosol annotations. supported_by: - reference_id: PMID:12090627 supporting_text: All GSTs except AtGSTF10 formed soluble proteins - reference_id: PMID:21712415 supporting_text: The fourth enzyme, GSTF6, lacks predicted signaling peptides and is therefore most likely cytosolic. - term: id: GO:0005739 label: mitochondrion evidence_type: HDA original_reference_id: PMID:12492832 qualifier: located_in review: summary: GSTF6 was detected in purified mitochondria from oxidatively stressed Arabidopsis cell cultures. action: MARK_AS_OVER_ANNOTATED reason: The authors themselves note that several stress-induced proteins in their fraction are generally considered extramitochondrial. GSTF6 has no mitochondrial targeting peptide and is strongly induced by H2O2. Its detection most likely reflects association or contamination of an abundant cytosolic protein, not a mitochondrial location. supported_by: - reference_id: PMID:12492832 supporting_text: Several others are generally considered to be extramitochondrial but are clearly present in a highly purified mitochondrial fraction used in this study and are known to play roles in stress response. - term: id: GO:0005739 label: mitochondrion evidence_type: HDA original_reference_id: PMID:14671022 qualifier: located_in review: summary: GSTF6 was detected in a large LC-MS/MS mitochondrial proteome. action: MARK_AS_OVER_ANNOTATED reason: GSTF6 lacks a mitochondrial presequence. Only about half of the proteins in this experimental set are predicted to be mitochondrial, so the dataset includes non-mitochondrial proteins. No targeted study places GSTF6 in mitochondria. supported_by: - reference_id: PMID:14671022 supporting_text: Only approximately half of the experimental set is predicted to be mitochondrial by targeting prediction programs - term: id: GO:0005829 label: cytosol evidence_type: HDA original_reference_id: PMID:25293756 qualifier: located_in review: summary: GSTF6 was identified in the crude cytosolic fraction of Arabidopsis leaves by size exclusion chromatography and LC-MS profiling. action: ACCEPT reason: This agrees with GSTF6 having no targeting peptide and with its soluble behaviour. The cytosol is the expected site of action, including for any contribution to the cytosolic glutathione-conjugate steps of camalexin biosynthesis. supported_by: - reference_id: PMID:25293756 supporting_text: Applying this approach to the crude cytosolic fraction of Arabidopsis thaliana leaves using size exclusion chromatography, we identified hundreds of cytosolic proteins - reference_id: PMID:21712415 supporting_text: The fourth enzyme, GSTF6, lacks predicted signaling peptides and is therefore most likely cytosolic. - term: id: GO:0005829 label: cytosol evidence_type: IEA original_reference_id: GO_REF:0000044 qualifier: located_in supporting_entities: - UniProtKB-SubCell:SL-0091 review: summary: UniProt subcellular location (Cytoplasm, cytosol) mapped to GO. action: ACCEPT reason: Consistent with the HDA cytosol annotation and with GSTF6 having no targeting peptide. supported_by: - reference_id: PMID:21712415 supporting_text: The fourth enzyme, GSTF6, lacks predicted signaling peptides and is therefore most likely cytosolic. - term: id: GO:0006749 label: glutathione metabolic process evidence_type: IBA original_reference_id: GO_REF:0000033 qualifier: involved_in supporting_entities: - PANTHER:PTN000136307 - SGD:S000003983 review: summary: Phylogenetic inference that GST family members take part in glutathione metabolism. action: ACCEPT reason: GSTF6 uses reduced glutathione as a co-substrate to form S-glutathione conjugates. For camalexin, the conjugate (GS-IAN) is processed further by GGP1/GGP3, so conjugate formation is a direct step of glutathione metabolism. The term is broad, but it is the right level for a GST whose specific physiological substrates are uncertain. supported_by: - reference_id: PMID:21239642 supporting_text: These results suggest that GSH is the Cys derivative used during camalexin biosynthesis - reference_id: PMID:12090627 supporting_text: All GSTs except AtGSTF10 formed soluble proteins which catalysed a specific range of glutathione conjugation or glutathione peroxidase activities. - term: id: GO:0006979 label: response to oxidative stress evidence_type: IEP original_reference_id: PMID:9501110 qualifier: acts_upstream_of_or_within review: summary: Expression-based annotation. A stress-inducible GST transcript was induced by the oxidative-stress-inducing herbicide acifluorfen, alongside the Trp pathway and camalexin. action: KEEP_AS_NON_CORE reason: GSTF6 is reliably induced by oxidative stress (H2O2, acifluorfen). IEP shows that its expression responds to the stress, not that GSTF6 carries out the response. Combined RNAi of GSTF6/7/9/10 gave only subtle changes. The annotation is reasonable as a non-core expression response. supported_by: - reference_id: PMID:9501110 supporting_text: The mRNAs for two stress-inducible enzymes unrelated to amino acid biosynthesis and accumulation of the indolic phytoalexin camalexin were also induced by amino acid starvation. - reference_id: PMID:9501110 supporting_text: treatments with the oxidative stress-inducing herbicide acifluorfen and the abiotic elicitor alpha-amino butyric acid induced responses similar to those induced by the amino acid starvation treatments - term: id: GO:0009407 label: toxin catabolic process evidence_type: IEA original_reference_id: GO_REF:0000117 qualifier: involved_in supporting_entities: - ARBA:ARBA00028091 review: summary: ARBA machine-learning inference that GSTs act in toxin catabolism. action: KEEP_AS_NON_CORE reason: Glutathione conjugation of xenobiotic electrophiles, including herbicides, is a well-established general role of plant GSTs. GSTF6 is induced by herbicides and safeners and has conjugating activity. However, no specific toxin has been shown to be detoxified by GSTF6 in planta, and its activity on the model substrate CDNB is low. This is a plausible family-level role, not a demonstrated core function. supported_by: - reference_id: PMID:12090627 supporting_text: Glutathione S-transferases (GSTs) appear to be ubiquitous in plants and have defined roles in herbicide detoxification. - term: id: GO:0009407 label: toxin catabolic process evidence_type: TAS original_reference_id: PMID:12090627 qualifier: acts_upstream_of_or_within review: summary: Author statement from the Arabidopsis GST family survey linking GSTs to herbicide detoxification. action: KEEP_AS_NON_CORE reason: The statement is about the GST family in general, and GSTF6 was shown to be herbicide-inducible and catalytically active. A GSTF6-specific toxin substrate has not been identified, so this is kept as non-core. supported_by: - reference_id: PMID:12090627 supporting_text: Glutathione S-transferases (GSTs) appear to be ubiquitous in plants and have defined roles in herbicide detoxification. - reference_id: PMID:12090627 supporting_text: AtGSTF6 was upregulated by all treatments - term: id: GO:0009414 label: response to water deprivation evidence_type: IEP original_reference_id: PMID:8253194 qualifier: acts_upstream_of_or_within review: summary: ERD11 (GSTF6) was isolated as a dehydration-inducible cDNA. action: KEEP_AS_NON_CORE reason: The paper directly shows dehydration-induced expression. It does not show a role for GSTF6 in drought tolerance, so this is a non-core expression response. supported_by: - reference_id: PMID:8253194 supporting_text: The expression of the genes for ERD11 and ERD13 was induced by dehydration - term: id: GO:0009505 label: plant-type cell wall evidence_type: HDA original_reference_id: PMID:16287169 qualifier: located_in review: summary: GSTF6 was detected in a MudPIT proteome of purified cell walls from suspension cells. action: MARK_AS_OVER_ANNOTATED reason: GSTF6 lacks a signal peptide, and the study itself relied on signal peptide prediction to select genuine extracellular proteins. A soluble cytosolic GST found in a wall preparation is best treated as a contaminant. supported_by: - reference_id: PMID:16287169 supporting_text: Using bioinformatics for the prediction of signal peptides for targeting to the secretory pathway and for the absence of ER retention signal, 89 proteins were selected as potential extracellular proteins. - term: id: GO:0009506 label: plasmodesma evidence_type: HDA original_reference_id: PMID:21533090 qualifier: located_in review: summary: GSTF6 was detected in the plasmodesmal proteome of Arabidopsis suspension cells. action: MARK_AS_OVER_ANNOTATED reason: The authors estimate that about a third of the PD-proteome consists of cytoplasmic contaminants. GSTF6 is an abundant, stress-induced cytosolic GST that has not been validated at plasmodesmata. supported_by: - reference_id: PMID:21533090 supporting_text: still has a significant number (35%) of putative cytoplasmic contaminants, probably reflecting the sensitivity of the proteomic detection system - term: id: GO:0009507 label: chloroplast evidence_type: ISM original_reference_id: GO_REF:0000122 qualifier: located_in review: summary: AtSubP sequence-based prediction of chloroplast localization. action: REMOVE reason: GSTF6 has no chloroplast transit peptide. It is described as lacking targeting peptides and is found in the cytosolic fraction. This computational prediction is contradicted by sequence and experimental localization data. supported_by: - reference_id: PMID:21712415 supporting_text: The fourth enzyme, GSTF6, lacks predicted signaling peptides and is therefore most likely cytosolic. - term: id: GO:0010494 label: cytoplasmic stress granule evidence_type: IDA original_reference_id: PMID:30664249 qualifier: located_in review: summary: GSTF6 was identified among proteins co-purifying with Rbp47b-GFP-marked stress granules after heat stress. action: KEEP_AS_NON_CORE reason: Stress granules form in the cytosol, so this is compatible with the cytosolic location of GSTF6. The authors note that many non-canonical SG proteins are enzymes that may be stored in SGs during stress. This is a plausible condition-specific location, but it is not part of GSTF6's core function. supported_by: - reference_id: PMID:30664249 supporting_text: Intriguingly, the remaining proteins were enriched in key enzymes and regulators - term: id: GO:0043295 label: glutathione binding evidence_type: IBA original_reference_id: GO_REF:0000033 qualifier: enables supporting_entities: - AGI_LocusCode:AT1G02920 - AGI_LocusCode:AT1G02930 - AGI_LocusCode:AT2G30860 - AGI_LocusCode:AT2G30870 - AGI_LocusCode:AT2G47730 - AGI_LocusCode:AT4G02520 - PANTHER:PTN000136955 - UniProtKB:P46420 review: summary: Phylogenetic inference of glutathione binding in the phi GST clade. GSTF6 (AT1G02930) is among the donors because of its own experimental annotation. action: ACCEPT reason: GSTF6 binds glutathione through its N-terminal G-site, and this binding is part of its glutathione transferase activity. The protein was experimentally retained on glutathione affinity media. The target appearing among the IBA donors reflects that experimental evidence, not circularity. supported_by: - reference_id: PMID:15159623 supporting_text: glutathione-affinity chromatography - term: id: GO:0043295 label: glutathione binding evidence_type: IDA original_reference_id: PMID:15159623 qualifier: enables review: summary: GSTF6 was purified from Arabidopsis cell culture by glutathione-affinity chromatography. action: ACCEPT reason: Retention on immobilized glutathione is direct evidence of glutathione binding. This fits the G-site of a phi GST and underlies its transferase activity. supported_by: - reference_id: PMID:15159623 supporting_text: we identified 20 GSTs at the protein level in Arabidopsis cell culture with a combination of GST antibody detection, LC-MS/MS analysis of 23-30 kDa proteins and glutathione-affinity chromatography - term: id: GO:0046686 label: response to cadmium ion evidence_type: IEP original_reference_id: PMID:17075075 qualifier: acts_upstream_of_or_within review: summary: GSTs including GSTF6 changed in abundance in the Arabidopsis root proteome after Cd2+ exposure. action: KEEP_AS_NON_CORE reason: Cadmium induction of GSTF6 is also reported independently (UniProt INDUCTION). This is an expression response to a stress, not a demonstrated role in cadmium tolerance. supported_by: - reference_id: PMID:17075075 supporting_text: Most of the identified proteins belong to four different classes - term: id: GO:0050897 label: cobalt ion binding evidence_type: HDA original_reference_id: PMID:20018591 qualifier: enables review: summary: GSTF6 was retained on Co2+-charged IMAC resin in a survey of metal-interacting mitochondrial proteins. action: MARK_AS_OVER_ANNOTATED reason: As for copper, IMAC retention shows surface residues that coordinate an immobilized metal, not a biological cobalt-binding function. GSTF6 is also not a mitochondrial protein. No cobalt-dependent function of GSTF6 is known. supported_by: - reference_id: PMID:20018591 supporting_text: Immobilized metal affinity chromatography charged with Cu(2+), Zn(2+), and Co(2+) was used to identify over 100 mitochondrial proteins with metal-binding properties. - term: id: GO:2001147 label: camalexin binding evidence_type: IDA original_reference_id: PMID:21631432 qualifier: enables review: summary: The source paper screened Arabidopsis phi GSTs for natural-product ligands. The abstract attributes selective camalexin binding to GSTF2. action: UNDECIDED reason: >- The cached abstract restricts heterocyclic-ligand binding "uniquely" to GSTF2 and GSTF3, and attributes camalexin and quercetin-3-O-rhamnoside (quercitrin) binding to GSTF2. In the GSTF nomenclature co-authored by the same group (Wagner, Edwards, Dixon & Mauch 2002, PMID:12090627, as recorded in UniProt), GSTF3 is At2g02930 (Q9SLM6), a different gene from GSTF6 (At1g02930, P42760), which carries only the legacy alias "AtGSTF3". A QuickGO query for PMID:21631432 (recorded in GSTF6-notes.md) returns the camalexin and quercitrin binding IDA annotations for GSTF2 (P46422) and GSTF6 (P42760) but none for Q9SLM6, which is the pattern expected if the paper's "GSTF3" was mapped to P42760 through that legacy alias. Whichever of GSTF2/GSTF3 the full text attributes the binding to, it is not GSTF6, and the abstract's "uniquely" wording excludes binding by the other GSTFs screened. The full text could not be read (it is not in PMC, and Portland Press and the Durham repository returned 403), so this rests on the abstract's explicit statement plus the nomenclature evidence, not on data the curator saw for GSTF6. Because the full text could not be read, CLAUDE.md requires UNDECIDED rather than REMOVE for an experimental row: the alias evidence points strongly to a name-collision mis-mapping, which TAIR should be asked to check against the full text. Camalexin binding is not biologically implausible for GSTF6, which is itself implicated in camalexin biosynthesis (GS-IAN formation); the mis-mapping concern rests on the abstract's "uniquely ... GSTF2 and GSTF3" wording and the alias collision, not on biology. supported_by: - reference_id: PMID:21631432 supporting_text: Uniquely, when overexpressed in bacteria, family members GSTF2 and GSTF3 bound a series of heterocyclic compounds - reference_id: file:ARATH/GSTF6/GSTF6-uniprot.txt record_section: [DE] supporting_text: 'AltName: Full=AtGSTF3;' - reference_id: file:ARATH/GSTF6/GSTF6-uniprot.txt record_section: ["CC:FUNCTION"] supporting_text: 'FUNCTION: Involved in camalexin biosynthesis by probably catalyzing the' - reference_id: PMID:21631432 supporting_text: GSTF2 also selectively bound the indole-derived phytoalexin camalexin, as well as the flavonol quercetin-3-O-rhamnoside - reference_id: file:ARATH/GSTF6/GSTF6-deep-research-falcon.md supporting_text: is an ambiguous historical alias source_defects: - defect_type: WRONG_GENE_PRODUCT resource: TAIR slot: DB_Object_ID requested_change: CHECK asserted_value: UniProtKB:P42760 cause: LEGACY_ALIAS confidence: PROBABLE explanation: >- PMID:21631432 reports heterocyclic-ligand binding "uniquely" for GSTF2 and GSTF3. In the phi-GST nomenclature, GSTF3 is At2g02930 (Q9SLM6). This annotation is instead on GSTF6 (At1g02930, P42760), whose only link to the name is the legacy alias "AtGSTF3". QuickGO returns this paper's binding IDAs for GSTF2 (P46422) and GSTF6 but none for Q9SLM6, the pattern expected from mapping the paper's "GSTF3" through the alias. We could not read the full text. Please check it: if GSTF3 was assayed, move the annotation to Q9SLM6; if only GSTF2 bound the ligand, delete this row. The abstract names GSTF3 only for the heterocyclics and attributes camalexin and quercetin-3-O-rhamnoside binding to GSTF2, so deletion is the more likely outcome for this ligand. supported_by: - reference_id: PMID:21631432 supporting_text: Uniquely, when overexpressed in bacteria, family members GSTF2 and GSTF3 bound a series of heterocyclic compounds - reference_id: PMID:21631432 supporting_text: GSTF2 also selectively bound the indole-derived phytoalexin camalexin, as well as the flavonol quercetin-3-O-rhamnoside - term: id: GO:2001227 label: quercitrin binding evidence_type: IDA original_reference_id: PMID:21631432 qualifier: enables review: summary: Same source as the camalexin binding annotation. The abstract attributes quercetin-3-O-rhamnoside binding to GSTF2. action: UNDECIDED reason: >- The cached abstract restricts heterocyclic-ligand binding "uniquely" to GSTF2 and GSTF3, and attributes camalexin and quercetin-3-O-rhamnoside (quercitrin) binding to GSTF2. In the GSTF nomenclature co-authored by the same group (Wagner, Edwards, Dixon & Mauch 2002, PMID:12090627, as recorded in UniProt), GSTF3 is At2g02930 (Q9SLM6), a different gene from GSTF6 (At1g02930, P42760), which carries only the legacy alias "AtGSTF3". A QuickGO query for PMID:21631432 (recorded in GSTF6-notes.md) returns the camalexin and quercitrin binding IDA annotations for GSTF2 (P46422) and GSTF6 (P42760) but none for Q9SLM6, which is the pattern expected if the paper's "GSTF3" was mapped to P42760 through that legacy alias. Whichever of GSTF2/GSTF3 the full text attributes the binding to, it is not GSTF6, and the abstract's "uniquely" wording excludes binding by the other GSTFs screened. The full text could not be read (it is not in PMC, and Portland Press and the Durham repository returned 403), so this rests on the abstract's explicit statement plus the nomenclature evidence, not on data the curator saw for GSTF6. Because the full text could not be read, CLAUDE.md requires UNDECIDED rather than REMOVE for an experimental row: the alias evidence points strongly to a name-collision mis-mapping, which TAIR should be asked to check against the full text. supported_by: - reference_id: PMID:21631432 supporting_text: Uniquely, when overexpressed in bacteria, family members GSTF2 and GSTF3 bound a series of heterocyclic compounds - reference_id: file:ARATH/GSTF6/GSTF6-uniprot.txt record_section: [DE] supporting_text: 'AltName: Full=AtGSTF3;' - reference_id: PMID:21631432 supporting_text: GSTF2 also selectively bound the indole-derived phytoalexin camalexin, as well as the flavonol quercetin-3-O-rhamnoside source_defects: - defect_type: WRONG_GENE_PRODUCT resource: TAIR slot: DB_Object_ID requested_change: CHECK asserted_value: UniProtKB:P42760 cause: LEGACY_ALIAS confidence: PROBABLE explanation: >- PMID:21631432 reports heterocyclic-ligand binding "uniquely" for GSTF2 and GSTF3. In the phi-GST nomenclature, GSTF3 is At2g02930 (Q9SLM6). This annotation is instead on GSTF6 (At1g02930, P42760), whose only link to the name is the legacy alias "AtGSTF3". QuickGO returns this paper's binding IDAs for GSTF2 (P46422) and GSTF6 but none for Q9SLM6, the pattern expected from mapping the paper's "GSTF3" through the alias. We could not read the full text. Please check it: if GSTF3 was assayed, move the annotation to Q9SLM6; if only GSTF2 bound the ligand, delete this row. The abstract names GSTF3 only for the heterocyclics and attributes camalexin and quercetin-3-O-rhamnoside binding to GSTF2, so deletion is the more likely outcome for this ligand. supported_by: - reference_id: PMID:21631432 supporting_text: Uniquely, when overexpressed in bacteria, family members GSTF2 and GSTF3 bound a series of heterocyclic compounds - reference_id: PMID:21631432 supporting_text: GSTF2 also selectively bound the indole-derived phytoalexin camalexin, as well as the flavonol quercetin-3-O-rhamnoside core_functions: - description: Cytosolic phi-class glutathione S-transferase that conjugates reduced glutathione to electrophilic substrates. It has been proposed to contribute, redundantly with other GSTs and with spontaneous chemistry, to conjugation of the activated indole-3-acetonitrile intermediate to form GS-IAN in camalexin biosynthesis, and more generally to stress-induced glutathione conjugation. molecular_function: id: GO:0004364 label: glutathione transferase activity directly_involved_in: - id: GO:0006749 label: glutathione metabolic process locations: - id: GO:0005829 label: cytosol supported_by: - reference_id: PMID:12090627 supporting_text: All GSTs except AtGSTF10 formed soluble proteins which catalysed a specific range of glutathione conjugation or glutathione peroxidase activities. - reference_id: PMID:21239642 supporting_text: Arabidopsis GSTF6 expressed in yeast cells catalyzed GSH(IAN) formation. - reference_id: PMID:21712415 supporting_text: The fourth enzyme, GSTF6, lacks predicted signaling peptides and is therefore most likely cytosolic. references: - id: GO_REF:0000033 title: Annotation inferences using phylogenetic trees 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: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: GO_REF:0000122 title: AtSubP analysis findings: [] - id: PMID:12090627 title: Probing the diversity of the Arabidopsis glutathione S-transferase gene family. findings: - statement: GSTF6 is induced by all tested stresses and recombinant GSTF6 is a soluble, active GST. supporting_text: AtGSTF6 was upregulated by all treatments - id: PMID:12492832 title: The impact of oxidative stress on Arabidopsis mitochondria. findings: [] - id: PMID:14671022 title: Experimental analysis of the Arabidopsis mitochondrial proteome highlights signaling and regulatory components, provides assessment of targeting prediction programs, and indicates plant-specific mitochondrial proteins. findings: [] - id: PMID:15159623 title: Proteomic analysis of glutathione S -transferases of Arabidopsis thaliana reveals differential salicylic acid-induced expression of the plant-specific phi and tau classes. findings: [] - id: PMID:15539469 title: The vegetative vacuole proteome of Arabidopsis thaliana reveals predicted and unexpected proteins. findings: [] - id: PMID:16287169 title: Arabidopsis cell wall proteome defined using multidimensional protein identification technology. findings: [] - id: PMID:16526091 title: Proteomic survey of copper-binding proteins in Arabidopsis roots by immobilized metal affinity chromatography and mass spectrometry. findings: [] - id: PMID:17075075 title: Proteome changes in Arabidopsis thaliana roots upon exposure to Cd2+. findings: [] - id: PMID:20018591 title: Divalent metal ions in plant mitochondria and their role in interactions with proteins and oxidative stress-induced damage to respiratory function. findings: [] - id: PMID:21533090 title: Arabidopsis plasmodesmal proteome. findings: [] - id: PMID:21631432 title: 'The Arabidopsis phi class glutathione transferase AtGSTF2: binding and regulation by biologically active heterocyclic ligands.' findings: [] reference_review: relevance: LOW correctness: UNVERIFIED review_notes: Abstract names GSTF2 (and GSTF3) as the ligand binders. GSTF6 is not named in the abstract, and the full text (Biochem J) was not accessible, so whether GSTF6 was assayed could not be verified. - id: PMID:21239642 title: Glutathione-indole-3-acetonitrile is required for camalexin biosynthesis in Arabidopsis thaliana. findings: - statement: gstf6 knockout reduces and GSTF6 overexpression increases camalexin; GSTF6 enhances GSH(IAN) formation in yeast. supporting_text: GSTF6 overexpression increased and GSTF6-knockout reduced camalexin production. reference_review: relevance: HIGH correctness: VERIFIED review_notes: PubMed-verified (Su et al. 2011 Plant Cell, doi 10.1105/tpc.110.079145). Full text (PMC3051237) indicates effects are modest (about 27-28% reduction in knockouts) and that control yeast also form GSH(IAN), so the data support a contributory rather than exclusive role. - id: PMID:21712415 title: Cytosolic γ-glutamyl peptidases process glutathione conjugates in the biosynthesis of glucosinolates and camalexin in Arabidopsis. findings: [] - id: PMID:23449503 title: 'Assigning gene function in biosynthetic pathways: camalexin and beyond.' findings: [] - id: PMID:25293756 title: A proteomic strategy for global analysis of plant protein complexes. findings: [] - id: PMID:28887381 title: Global Analysis of Membrane-associated Protein Oligomerization Using Protein Correlation Profiling. findings: [] - id: PMID:30664249 title: Protein and metabolite composition of Arabidopsis stress granules. findings: [] - id: PMID:31511315 title: The Formation of a Camalexin Biosynthetic Metabolon. findings: - statement: GSTU4, not GSTF6, is the GST recruited to the camalexin P450 complex, and GSTU4 is not a camalexin biosynthetic enzyme. supporting_text: This shows that GSTU4 is not directly involved in camalexin biosynthesis but rather plays a role in a competing mechanism. - id: PMID:8253194 title: Characterization of two cDNAs (ERD11 and ERD13) for dehydration-inducible genes that encode putative glutathione S-transferases in Arabidopsis thaliana L. findings: [] - id: PMID:9501110 title: Induction of Arabidopsis tryptophan pathway enzymes and camalexin by amino acid starvation, oxidative stress, and an abiotic elicitor. findings: [] - id: file:ARATH/GSTF6/GSTF6-deep-research-falcon.md title: GSTF6 deep research (falcon) findings: [] suggested_questions: - question: Should GSTF6 be annotated to camalexin biosynthetic process (GO:0010120)? Su et al. 2011 show modest knockout and overexpression effects and enhanced GS-IAN formation in yeast. Against this, higher-order gstf2 gstf3 gstf6 (gstf7) mutants show no camalexin defect, most Arabidopsis GSTs support GS-IAN formation, and the indole cyanohydrin intermediate reacts spontaneously with glutathione. Is the catalytic contribution of GSTF6 large enough in planta to count as participation? - question: Were GSTF6 (At1g02930) data actually reported in Dixon et al. 2011 for camalexin and quercitrin binding, or do these annotations come from the historical AtGSTF3 alias of GSTF6 being confused with the current GSTF3 (At2g02930)? - question: What is the physiological electrophile conjugated by GSTF6 under the many stresses that induce it? suggested_experiments: - description: Steady-state kinetics of purified GSTF6 against chemically generated indole cyanohydrin / dehydro-IAN, with the uncatalysed rate measured in parallel, to quantify how much GSTF6 accelerates GS-IAN formation. - description: Camalexin and GS-IAN profiling in higher-order phi and tau GST mutants (e.g. gstf6 gstf7 combined with other camalexin-coexpressed GSTs) after Botrytis infection rather than AgNO3, to test redundancy under pathogen-relevant conditions.