GFER encodes ALR/Erv1, a FAD-dependent sulfhydryl oxidase in the mitochondrial intermembrane space. Its core role is to re-oxidize MIA40/CHCHD4 in the mitochondrial disulfide relay, enabling oxidative folding and import/retention of cysteine-rich IMS proteins.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0016971 flavin-dependent sulfhydryl oxidase activity | IBA GO_REF:0000033 | ACCEPT | Summary: Correct and core. GFER/ALR is the FAD-linked sulfhydryl oxidase of the mitochondrial disulfide relay. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The literature retrieved consistently maps **human GFER** to **ALR (augmenter of liver regeneration)** and the mammalian homolog of **yeast Erv1**, a **FAD-linked sulfhydryl oxidase** functioning in the **mitochondrial IMS disulfide relay**. This matches the UniProt P55789 description (FAD-linked sulfhydryl oxidase ALR; EC 1.8.3.2; aliases ALR/HERV1/HPO). (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 16-19) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) file:human/GFER/GFER-deep-research-falcon.md | Enzymatic activity (EC 1.8.3.2) | GFER/ALR is a **sulfhydryl oxidase** that re-oxidizes **MIA40/CHCHD4** after MIA40 oxidizes incoming IMS substrates. Electron flow is **substrate thiols → MIA40 CPC → ALR shuttle motif → ALR core CXXC/CAAC-CEEC → FAD → terminal acceptor (primarily cytochrome c, alternatively O2)**, thereby enabling de novo disulfide formation and repeated oxidative folding cycles. | (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31, finger2020proteinimportby pages 8-10) | 2024-06, https://doi.org/10.1002/2211-5463.13839 ; 2020-03, https://doi.org/10.1515/hsz-2020-0108 | |
| GO:0001889 liver development | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: Keep as non-core. ALR has historical growth factor/liver-regeneration biology, but the primary mechanistically defined function of UniProt P55789 is IMS sulfhydryl oxidase activity. Reason: Liver development/regeneration is a downstream or isoform/context-associated phenotype, not the core molecular function. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md Older review literature notes reports of non-mitochondrial ALR forms (cytosolic/nuclear/secreted growth factor activities), but for **functional annotation of UniProt P55789**, the mechanistically defined and disease-linked role is the mitochondrial IMS sulfhydryl oxidase in the disulfide relay. (fischer2013themitochondrialdisulfide pages 6-7) PMID:20593814 The short form (sfALR, 15 kDa; starting at M81 of the human long form, lfALR, sequence depicted in Figure 1A) is a circulating growth factor (11, 12, 15, 17, 18) and interacts with specific receptors on the cell surface (19, 20). |
| GO:0005576 extracellular region | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Keep as non-core. extracellular region is consistent with reports of short/non-mitochondrial ALR forms, but the core reviewed function is long ALR in the mitochondrial intermembrane space. Reason: Retain as non-core because non-mitochondrial ALR forms are reported, while prioritizing IMS disulfide-relay function. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md A hepatology review summarizes **two principal ALR isoforms**, approximately **~15 kDa (short)** and **~22 kDa (long)**; the **long isoform** functions in the mitochondrial IMS as a core MIA/disulfide relay component. (nalesnik2017augmenterofliver pages 1-4) file:human/GFER/GFER-deep-research-falcon.md Older review literature notes reports of non-mitochondrial ALR forms (cytosolic/nuclear/secreted growth factor activities), but for **functional annotation of UniProt P55789**, the mechanistically defined and disease-linked role is the mitochondrial IMS sulfhydryl oxidase in the disulfide relay. (fischer2013themitochondrialdisulfide pages 6-7) |
| GO:0005737 cytoplasm | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Keep as non-core. cytoplasm is consistent with reports of short/non-mitochondrial ALR forms, but the core reviewed function is long ALR in the mitochondrial intermembrane space. Reason: Retain as non-core because non-mitochondrial ALR forms are reported, while prioritizing IMS disulfide-relay function. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md A hepatology review summarizes **two principal ALR isoforms**, approximately **~15 kDa (short)** and **~22 kDa (long)**; the **long isoform** functions in the mitochondrial IMS as a core MIA/disulfide relay component. (nalesnik2017augmenterofliver pages 1-4) file:human/GFER/GFER-deep-research-falcon.md Older review literature notes reports of non-mitochondrial ALR forms (cytosolic/nuclear/secreted growth factor activities), but for **functional annotation of UniProt P55789**, the mechanistically defined and disease-linked role is the mitochondrial IMS sulfhydryl oxidase in the disulfide relay. (fischer2013themitochondrialdisulfide pages 6-7) |
| GO:0005739 mitochondrion | IEA GO_REF:0000044 | MARK AS OVER ANNOTATED | Summary: Correct but broad. GFER/long ALR is specifically localized to the mitochondrial intermembrane space. Reason: Prefer mitochondrial intermembrane space and mitochondrial disulfide relay system over generic mitochondrion. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The best-supported primary functional localization of long ALR is the **mitochondrial intermembrane space**, where it operates in oxidative folding/protein import with MIA40. (zarges2024oxidativeproteinfolding pages 8-9, nalesnik2017augmenterofliver pages 1-4) |
| GO:0005758 mitochondrial intermembrane space | IEA GO_REF:0000044 | ACCEPT | Summary: Correct and core. Long ALR/GFER functions in the mitochondrial intermembrane space. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The best-supported primary functional localization of long ALR is the **mitochondrial intermembrane space**, where it operates in oxidative folding/protein import with MIA40. (zarges2024oxidativeproteinfolding pages 8-9, nalesnik2017augmenterofliver pages 1-4) file:human/GFER/GFER-deep-research-falcon.md A hepatology review summarizes **two principal ALR isoforms**, approximately **~15 kDa (short)** and **~22 kDa (long)**; the **long isoform** functions in the mitochondrial IMS as a core MIA/disulfide relay component. (nalesnik2017augmenterofliver pages 1-4) |
| GO:0015035 protein-disulfide reductase activity | IEA GO_REF:0000117 | MODIFY | Summary: The disulfide-relay context is right, but reductase is the wrong direction for GFER. GFER oxidizes thiols/re-oxidizes MIA40 as a sulfhydryl oxidase. Reason: Replace protein-disulfide reductase activity with sulfhydryl/thiol oxidase activity for GFER. Proposed replacements: flavin-dependent sulfhydryl oxidase activity thiol oxidase activity Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The IMS contains an oxidative folding/import pathway in which incoming cysteine-rich proteins are oxidized and trapped in the IMS by formation of disulfide bonds. In mammals, the core catalytic pair is **MIA40/CHCHD4 (oxidoreductase)** and **ALR/GFER (sulfhydryl oxidase)**. ALR’s central biochemical function is to **regenerate oxidized MIA40** after MIA40 transfers disulfides to substrates. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 8-10) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) file:human/GFER/GFER-deep-research-falcon.md | Enzymatic activity (EC 1.8.3.2) | GFER/ALR is a **sulfhydryl oxidase** that re-oxidizes **MIA40/CHCHD4** after MIA40 oxidizes incoming IMS substrates. Electron flow is **substrate thiols → MIA40 CPC → ALR shuttle motif → ALR core CXXC/CAAC-CEEC → FAD → terminal acceptor (primarily cytochrome c, alternatively O2)**, thereby enabling de novo disulfide formation and repeated oxidative folding cycles. | (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31, finger2020proteinimportby pages 8-10) | 2024-06, https://doi.org/10.1002/2211-5463.13839 ; 2020-03, https://doi.org/10.1515/hsz-2020-0108 | |
| GO:0016971 flavin-dependent sulfhydryl oxidase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Correct and core. GFER/ALR is the FAD-linked sulfhydryl oxidase of the mitochondrial disulfide relay. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The literature retrieved consistently maps **human GFER** to **ALR (augmenter of liver regeneration)** and the mammalian homolog of **yeast Erv1**, a **FAD-linked sulfhydryl oxidase** functioning in the **mitochondrial IMS disulfide relay**. This matches the UniProt P55789 description (FAD-linked sulfhydryl oxidase ALR; EC 1.8.3.2; aliases ALR/HERV1/HPO). (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 16-19) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) file:human/GFER/GFER-deep-research-falcon.md | Enzymatic activity (EC 1.8.3.2) | GFER/ALR is a **sulfhydryl oxidase** that re-oxidizes **MIA40/CHCHD4** after MIA40 oxidizes incoming IMS substrates. Electron flow is **substrate thiols → MIA40 CPC → ALR shuttle motif → ALR core CXXC/CAAC-CEEC → FAD → terminal acceptor (primarily cytochrome c, alternatively O2)**, thereby enabling de novo disulfide formation and repeated oxidative folding cycles. | (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31, finger2020proteinimportby pages 8-10) | 2024-06, https://doi.org/10.1002/2211-5463.13839 ; 2020-03, https://doi.org/10.1515/hsz-2020-0108 | |
| GO:0016972 thiol oxidase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Correct. Thiol oxidase activity captures the sulfhydryl oxidase chemistry of ALR/GFER. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) file:human/GFER/GFER-deep-research-falcon.md | Enzymatic activity (EC 1.8.3.2) | GFER/ALR is a **sulfhydryl oxidase** that re-oxidizes **MIA40/CHCHD4** after MIA40 oxidizes incoming IMS substrates. Electron flow is **substrate thiols → MIA40 CPC → ALR shuttle motif → ALR core CXXC/CAAC-CEEC → FAD → terminal acceptor (primarily cytochrome c, alternatively O2)**, thereby enabling de novo disulfide formation and repeated oxidative folding cycles. | (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31, finger2020proteinimportby pages 8-10) | 2024-06, https://doi.org/10.1002/2211-5463.13839 ; 2020-03, https://doi.org/10.1515/hsz-2020-0108 | |
| GO:0005515 protein binding | IPI PMID:25416956 A proteome-scale map of the human interactome network. | MARK AS OVER ANNOTATED | Summary: Protein binding is too generic for GFER. The informative role is FAD-dependent sulfhydryl oxidase activity in the MIA40/CHCHD4 disulfide relay. Reason: Replace generic interaction capture with sulfhydryl oxidase activity and mitochondrial disulfide relay system annotations. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The IMS contains an oxidative folding/import pathway in which incoming cysteine-rich proteins are oxidized and trapped in the IMS by formation of disulfide bonds. In mammals, the core catalytic pair is **MIA40/CHCHD4 (oxidoreductase)** and **ALR/GFER (sulfhydryl oxidase)**. ALR’s central biochemical function is to **regenerate oxidized MIA40** after MIA40 transfers disulfides to substrates. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 8-10) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) |
| GO:0005515 protein binding | IPI PMID:32353859 A SARS-CoV-2 protein interaction map reveals targets for dru... | MARK AS OVER ANNOTATED | Summary: Protein binding is too generic for GFER. The informative role is FAD-dependent sulfhydryl oxidase activity in the MIA40/CHCHD4 disulfide relay. Reason: Replace generic interaction capture with sulfhydryl oxidase activity and mitochondrial disulfide relay system annotations. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The IMS contains an oxidative folding/import pathway in which incoming cysteine-rich proteins are oxidized and trapped in the IMS by formation of disulfide bonds. In mammals, the core catalytic pair is **MIA40/CHCHD4 (oxidoreductase)** and **ALR/GFER (sulfhydryl oxidase)**. ALR’s central biochemical function is to **regenerate oxidized MIA40** after MIA40 transfers disulfides to substrates. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 8-10) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) |
| GO:0005515 protein binding | IPI PMID:33060197 Comparative host-coronavirus protein interaction networks re... | MARK AS OVER ANNOTATED | Summary: Protein binding is too generic for GFER. The informative role is FAD-dependent sulfhydryl oxidase activity in the MIA40/CHCHD4 disulfide relay. Reason: Replace generic interaction capture with sulfhydryl oxidase activity and mitochondrial disulfide relay system annotations. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The IMS contains an oxidative folding/import pathway in which incoming cysteine-rich proteins are oxidized and trapped in the IMS by formation of disulfide bonds. In mammals, the core catalytic pair is **MIA40/CHCHD4 (oxidoreductase)** and **ALR/GFER (sulfhydryl oxidase)**. ALR’s central biochemical function is to **regenerate oxidized MIA40** after MIA40 transfers disulfides to substrates. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 8-10) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) |
| GO:0005515 protein binding | IPI PMID:36217030 A comprehensive SARS-CoV-2-human protein-protein interactome... | MARK AS OVER ANNOTATED | Summary: Protein binding is too generic for GFER. The informative role is FAD-dependent sulfhydryl oxidase activity in the MIA40/CHCHD4 disulfide relay. Reason: Replace generic interaction capture with sulfhydryl oxidase activity and mitochondrial disulfide relay system annotations. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The IMS contains an oxidative folding/import pathway in which incoming cysteine-rich proteins are oxidized and trapped in the IMS by formation of disulfide bonds. In mammals, the core catalytic pair is **MIA40/CHCHD4 (oxidoreductase)** and **ALR/GFER (sulfhydryl oxidase)**. ALR’s central biochemical function is to **regenerate oxidized MIA40** after MIA40 transfers disulfides to substrates. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 8-10) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) |
| GO:0005739 mitochondrion | IDA GO_REF:0000052 | MARK AS OVER ANNOTATED | Summary: Correct but broad. GFER/long ALR is specifically localized to the mitochondrial intermembrane space. Reason: Prefer mitochondrial intermembrane space and mitochondrial disulfide relay system over generic mitochondrion. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The best-supported primary functional localization of long ALR is the **mitochondrial intermembrane space**, where it operates in oxidative folding/protein import with MIA40. (zarges2024oxidativeproteinfolding pages 8-9, nalesnik2017augmenterofliver pages 1-4) |
| GO:0005829 cytosol | IDA GO_REF:0000052 | KEEP AS NON CORE | Summary: Keep as non-core. cytosol is consistent with reports of short/non-mitochondrial ALR forms, but the core reviewed function is long ALR in the mitochondrial intermembrane space. Reason: Retain as non-core because non-mitochondrial ALR forms are reported, while prioritizing IMS disulfide-relay function. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md A hepatology review summarizes **two principal ALR isoforms**, approximately **~15 kDa (short)** and **~22 kDa (long)**; the **long isoform** functions in the mitochondrial IMS as a core MIA/disulfide relay component. (nalesnik2017augmenterofliver pages 1-4) file:human/GFER/GFER-deep-research-falcon.md Older review literature notes reports of non-mitochondrial ALR forms (cytosolic/nuclear/secreted growth factor activities), but for **functional annotation of UniProt P55789**, the mechanistically defined and disease-linked role is the mitochondrial IMS sulfhydryl oxidase in the disulfide relay. (fischer2013themitochondrialdisulfide pages 6-7) |
| GO:0016971 flavin-dependent sulfhydryl oxidase activity | EXP PMID:20593814 Structure of the human sulfhydryl oxidase augmenter of liver... | ACCEPT | Summary: Correct and core. GFER/ALR is the FAD-linked sulfhydryl oxidase of the mitochondrial disulfide relay. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The literature retrieved consistently maps **human GFER** to **ALR (augmenter of liver regeneration)** and the mammalian homolog of **yeast Erv1**, a **FAD-linked sulfhydryl oxidase** functioning in the **mitochondrial IMS disulfide relay**. This matches the UniProt P55789 description (FAD-linked sulfhydryl oxidase ALR; EC 1.8.3.2; aliases ALR/HERV1/HPO). (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 16-19) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) file:human/GFER/GFER-deep-research-falcon.md | Enzymatic activity (EC 1.8.3.2) | GFER/ALR is a **sulfhydryl oxidase** that re-oxidizes **MIA40/CHCHD4** after MIA40 oxidizes incoming IMS substrates. Electron flow is **substrate thiols → MIA40 CPC → ALR shuttle motif → ALR core CXXC/CAAC-CEEC → FAD → terminal acceptor (primarily cytochrome c, alternatively O2)**, thereby enabling de novo disulfide formation and repeated oxidative folding cycles. | (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31, finger2020proteinimportby pages 8-10) | 2024-06, https://doi.org/10.1002/2211-5463.13839 ; 2020-03, https://doi.org/10.1515/hsz-2020-0108 | |
| GO:0016971 flavin-dependent sulfhydryl oxidase activity | EXP PMID:22224850 An electron-transfer path through an extended disulfide rela... | ACCEPT | Summary: Correct and core. GFER/ALR is the FAD-linked sulfhydryl oxidase of the mitochondrial disulfide relay. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The literature retrieved consistently maps **human GFER** to **ALR (augmenter of liver regeneration)** and the mammalian homolog of **yeast Erv1**, a **FAD-linked sulfhydryl oxidase** functioning in the **mitochondrial IMS disulfide relay**. This matches the UniProt P55789 description (FAD-linked sulfhydryl oxidase ALR; EC 1.8.3.2; aliases ALR/HERV1/HPO). (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 16-19) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) file:human/GFER/GFER-deep-research-falcon.md | Enzymatic activity (EC 1.8.3.2) | GFER/ALR is a **sulfhydryl oxidase** that re-oxidizes **MIA40/CHCHD4** after MIA40 oxidizes incoming IMS substrates. Electron flow is **substrate thiols → MIA40 CPC → ALR shuttle motif → ALR core CXXC/CAAC-CEEC → FAD → terminal acceptor (primarily cytochrome c, alternatively O2)**, thereby enabling de novo disulfide formation and repeated oxidative folding cycles. | (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31, finger2020proteinimportby pages 8-10) | 2024-06, https://doi.org/10.1002/2211-5463.13839 ; 2020-03, https://doi.org/10.1515/hsz-2020-0108 | |
| GO:0016972 thiol oxidase activity | EXP PMID:20593814 Structure of the human sulfhydryl oxidase augmenter of liver... | ACCEPT | Summary: Correct. Thiol oxidase activity captures the sulfhydryl oxidase chemistry of ALR/GFER. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) file:human/GFER/GFER-deep-research-falcon.md | Enzymatic activity (EC 1.8.3.2) | GFER/ALR is a **sulfhydryl oxidase** that re-oxidizes **MIA40/CHCHD4** after MIA40 oxidizes incoming IMS substrates. Electron flow is **substrate thiols → MIA40 CPC → ALR shuttle motif → ALR core CXXC/CAAC-CEEC → FAD → terminal acceptor (primarily cytochrome c, alternatively O2)**, thereby enabling de novo disulfide formation and repeated oxidative folding cycles. | (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31, finger2020proteinimportby pages 8-10) | 2024-06, https://doi.org/10.1002/2211-5463.13839 ; 2020-03, https://doi.org/10.1515/hsz-2020-0108 | |
| GO:0016972 thiol oxidase activity | EXP PMID:22224850 An electron-transfer path through an extended disulfide rela... | ACCEPT | Summary: Correct. Thiol oxidase activity captures the sulfhydryl oxidase chemistry of ALR/GFER. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) file:human/GFER/GFER-deep-research-falcon.md | Enzymatic activity (EC 1.8.3.2) | GFER/ALR is a **sulfhydryl oxidase** that re-oxidizes **MIA40/CHCHD4** after MIA40 oxidizes incoming IMS substrates. Electron flow is **substrate thiols → MIA40 CPC → ALR shuttle motif → ALR core CXXC/CAAC-CEEC → FAD → terminal acceptor (primarily cytochrome c, alternatively O2)**, thereby enabling de novo disulfide formation and repeated oxidative folding cycles. | (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31, finger2020proteinimportby pages 8-10) | 2024-06, https://doi.org/10.1002/2211-5463.13839 ; 2020-03, https://doi.org/10.1515/hsz-2020-0108 | |
| GO:0160203 mitochondrial disulfide relay system | IDA PMID:21383138 Molecular recognition and substrate mimicry drive the electr... | ACCEPT | Summary: Correct and core. GFER/ALR re-oxidizes MIA40/CHCHD4 in the mitochondrial disulfide relay system. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The IMS contains an oxidative folding/import pathway in which incoming cysteine-rich proteins are oxidized and trapped in the IMS by formation of disulfide bonds. In mammals, the core catalytic pair is **MIA40/CHCHD4 (oxidoreductase)** and **ALR/GFER (sulfhydryl oxidase)**. ALR’s central biochemical function is to **regenerate oxidized MIA40** after MIA40 transfers disulfides to substrates. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 8-10) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) file:human/GFER/GFER-deep-research-falcon.md | Enzymatic activity (EC 1.8.3.2) | GFER/ALR is a **sulfhydryl oxidase** that re-oxidizes **MIA40/CHCHD4** after MIA40 oxidizes incoming IMS substrates. Electron flow is **substrate thiols → MIA40 CPC → ALR shuttle motif → ALR core CXXC/CAAC-CEEC → FAD → terminal acceptor (primarily cytochrome c, alternatively O2)**, thereby enabling de novo disulfide formation and repeated oxidative folding cycles. | (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31, finger2020proteinimportby pages 8-10) | 2024-06, https://doi.org/10.1002/2211-5463.13839 ; 2020-03, https://doi.org/10.1515/hsz-2020-0108 | |
| GO:0005739 mitochondrion | HTP PMID:34800366 Quantitative high-confidence human mitochondrial proteome an... | MARK AS OVER ANNOTATED | Summary: Correct but broad. GFER/long ALR is specifically localized to the mitochondrial intermembrane space. Reason: Prefer mitochondrial intermembrane space and mitochondrial disulfide relay system over generic mitochondrion. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The best-supported primary functional localization of long ALR is the **mitochondrial intermembrane space**, where it operates in oxidative folding/protein import with MIA40. (zarges2024oxidativeproteinfolding pages 8-9, nalesnik2017augmenterofliver pages 1-4) |
| GO:0005515 protein binding | IPI PMID:23676665 Protein import and oxidative folding in the mitochondrial in... | MARK AS OVER ANNOTATED | Summary: Protein binding is too generic for GFER. The informative role is FAD-dependent sulfhydryl oxidase activity in the MIA40/CHCHD4 disulfide relay. Reason: Replace generic interaction capture with sulfhydryl oxidase activity and mitochondrial disulfide relay system annotations. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The IMS contains an oxidative folding/import pathway in which incoming cysteine-rich proteins are oxidized and trapped in the IMS by formation of disulfide bonds. In mammals, the core catalytic pair is **MIA40/CHCHD4 (oxidoreductase)** and **ALR/GFER (sulfhydryl oxidase)**. ALR’s central biochemical function is to **regenerate oxidized MIA40** after MIA40 transfers disulfides to substrates. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 8-10) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) |
| GO:0005739 mitochondrion | IDA PMID:23676665 Protein import and oxidative folding in the mitochondrial in... | MARK AS OVER ANNOTATED | Summary: Correct but broad. GFER/long ALR is specifically localized to the mitochondrial intermembrane space. Reason: Prefer mitochondrial intermembrane space and mitochondrial disulfide relay system over generic mitochondrion. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The best-supported primary functional localization of long ALR is the **mitochondrial intermembrane space**, where it operates in oxidative folding/protein import with MIA40. (zarges2024oxidativeproteinfolding pages 8-9, nalesnik2017augmenterofliver pages 1-4) |
| GO:0015035 protein-disulfide reductase activity | IDA PMID:22224850 An electron-transfer path through an extended disulfide rela... | MODIFY | Summary: The disulfide-relay context is right, but reductase is the wrong direction for GFER. GFER oxidizes thiols/re-oxidizes MIA40 as a sulfhydryl oxidase. Reason: Replace protein-disulfide reductase activity with sulfhydryl/thiol oxidase activity for GFER. Proposed replacements: flavin-dependent sulfhydryl oxidase activity thiol oxidase activity Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The IMS contains an oxidative folding/import pathway in which incoming cysteine-rich proteins are oxidized and trapped in the IMS by formation of disulfide bonds. In mammals, the core catalytic pair is **MIA40/CHCHD4 (oxidoreductase)** and **ALR/GFER (sulfhydryl oxidase)**. ALR’s central biochemical function is to **regenerate oxidized MIA40** after MIA40 transfers disulfides to substrates. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 8-10) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) file:human/GFER/GFER-deep-research-falcon.md | Enzymatic activity (EC 1.8.3.2) | GFER/ALR is a **sulfhydryl oxidase** that re-oxidizes **MIA40/CHCHD4** after MIA40 oxidizes incoming IMS substrates. Electron flow is **substrate thiols → MIA40 CPC → ALR shuttle motif → ALR core CXXC/CAAC-CEEC → FAD → terminal acceptor (primarily cytochrome c, alternatively O2)**, thereby enabling de novo disulfide formation and repeated oxidative folding cycles. | (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31, finger2020proteinimportby pages 8-10) | 2024-06, https://doi.org/10.1002/2211-5463.13839 ; 2020-03, https://doi.org/10.1515/hsz-2020-0108 | |
| GO:0050660 flavin adenine dinucleotide binding | IDA PMID:22224850 An electron-transfer path through an extended disulfide rela... | ACCEPT | Summary: Correct. GFER/ALR is a FAD-linked sulfhydryl oxidase with a noncovalently bound FAD cofactor. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The literature retrieved consistently maps **human GFER** to **ALR (augmenter of liver regeneration)** and the mammalian homolog of **yeast Erv1**, a **FAD-linked sulfhydryl oxidase** functioning in the **mitochondrial IMS disulfide relay**. This matches the UniProt P55789 description (FAD-linked sulfhydryl oxidase ALR; EC 1.8.3.2; aliases ALR/HERV1/HPO). (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 16-19) file:human/GFER/GFER-deep-research-falcon.md - ALR contains an **N-terminal shuttle domain** with a redox-active **CRAC** motif and a **core domain** containing a redox-active **CAAC (CXXC-like)** motif and a **noncovalently bound FAD**. (zarges2024oxidativeproteinfolding pages 8-9) |
| GO:0005515 protein binding | IPI PMID:12681488 The apoptosis-associated protein BNIPL interacts with two ce... | MARK AS OVER ANNOTATED | Summary: Protein binding is too generic for GFER. The informative role is FAD-dependent sulfhydryl oxidase activity in the MIA40/CHCHD4 disulfide relay. Reason: Replace generic interaction capture with sulfhydryl oxidase activity and mitochondrial disulfide relay system annotations. Supporting Evidence: file:human/GFER/GFER-deep-research-falcon.md The IMS contains an oxidative folding/import pathway in which incoming cysteine-rich proteins are oxidized and trapped in the IMS by formation of disulfide bonds. In mammals, the core catalytic pair is **MIA40/CHCHD4 (oxidoreductase)** and **ALR/GFER (sulfhydryl oxidase)**. ALR’s central biochemical function is to **regenerate oxidized MIA40** after MIA40 transfers disulfides to substrates. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 8-10) file:human/GFER/GFER-deep-research-falcon.md ALR/GFER is a **FAD-dependent sulfhydryl oxidase** whose direct physiological substrate is the **reduced CPC motif of MIA40/CHCHD4**. It accepts electrons from reduced MIA40, transfers them through its own redox-active cysteine motifs to FAD, and then reduces downstream electron acceptors (primarily cytochrome c), thereby enabling repeated rounds of oxidative folding and IMS protein biogenesis. (zarges2024oxidativeproteinfolding pages 8-9, finger2020proteinimportby pages 25-31) |
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Download this section (compressed HTML)Q: How do short and long GFER/ALR isoforms divide mitochondrial IMS oxidase function from reported cytosolic or extracellular activities?
Q: Which ALR electron acceptor routes dominate in human cells under respiratory stress or MIA pathway inhibition?
Experiment: Rescue GFER-deficient cells with wild-type and variant ALR, then quantify FAD retention, MIA40 redox state, import/oxidation of cysteine-rich IMS substrates, and respiratory complex assembly.
Hypothesis: Disease-associated GFER variants primarily impair IMS substrate biogenesis by destabilizing FAD-linked ALR rather than abolishing all residual catalytic chemistry.
Experiment: Express isoform-specific GFER constructs with compartment-restricted tags and compare localization, secreted/cytosolic signaling readouts, and rescue of MIA pathway substrate import.
Hypothesis: Reported non-mitochondrial ALR activities are isoform-specific and separable from long-isoform IMS disulfide-relay function.
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