Affinage

SUMF1

Formylglycine-generating enzyme · UniProt Q8NBK3

Length
374 aa
Mass
40.6 kDa
Annotated
2026-04-28
42 papers in source corpus 11 papers cited in narrative 13 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

SUMF1 encodes the formylglycine-generating enzyme (FGE), a copper-dependent oxidase that post-translationally converts a conserved active-site cysteine to Cα-formylglycine in all known sulfatases, a modification essential for sulfate ester hydrolysis (PMID:14563551, PMID:31161504). FGE resides primarily in the endoplasmic reticulum, where its retention and secretion are dynamically regulated by sequential interactions with PDI (which couples retention and activation), ERGIC-53 (which promotes ER export and prevents proteasomal degradation), and ERp44 (which retrieves secreted FGE back to the ER), enabling both cell-autonomous sulfatase activation and paracrine activity (PMID:18508857). Co-expression of SUMF1 with individual sulfatases synergistically enhances their enzymatic activity in vitro and in vivo, including correction of glycosaminoglycan storage and neurological deficits in mouse models of mucopolysaccharidosis IIIA (PMID:17206939, PMID:17725987). Hypomorphic SUMF1 mutations that reduce both FGE catalytic activity and protein stability cause multiple sulfatase deficiency (MSD), with clinical severity proportional to the degree of residual FGE function; complete loss of SUMF1 is predicted to be lethal (PMID:17657823, PMID:21224894).

Mechanistic history

Synthesis pass · year-by-year structured walk · 7 steps
  1. 2003 High

    The gene responsible for generating the catalytic formylglycine residue in all sulfatases was identified as SUMF1, establishing it as the master activator of the entire sulfatase family and defining a new conserved gene family.

    Evidence Bioinformatic and biochemical identification of SUMF1/FGE as the Cα-formylglycine-generating enzyme

    PMID:14563551

    Open questions at the time
    • Catalytic mechanism (cofactor requirement) not yet determined
    • Paralog SUMF2 function unknown
    • Structural basis for substrate recognition unclear
  2. 2004 High

    Functional co-expression studies demonstrated that SUMF1 directly enhances sulfatase activity and that MSD-causing missense mutations impair this activity, establishing the genotype-phenotype link for multiple sulfatase deficiency.

    Evidence Co-expression of SUMF1 wild-type and mutants with individual sulfatases in COS-7 cells; enzymatic activity assays

    PMID:15146462

    Open questions at the time
    • Molecular basis for differential effects of mutations on different sulfatases not resolved
    • Protein stability vs. catalytic deficiency not yet dissected
  3. 2007 High

    In vivo co-delivery of SUMF1 with sulfatases via AAV vectors demonstrated therapeutic synergy, clearing lysosomal storage and improving neurological function in MPS-IIIA mice, while knockout rescue experiments established that all MSD mutations are hypomorphic and complete SUMF1 loss is likely lethal.

    Evidence AAV-mediated co-delivery in patient cells and MPS-IIIA mouse brain; Sumf1-/- MEF rescue with MSD mutants; behavioral, histological, and biochemical readouts

    PMID:17206939 PMID:17657823 PMID:17725987

    Open questions at the time
    • Therapeutic window and long-term efficacy of gene therapy not established
    • Whether any SUMF1 null human exists remains unclear
    • Contribution of secreted/paracrine FGE to in vivo correction not quantified
  4. 2008 High

    The ER trafficking mechanism of FGE was resolved: despite lacking canonical retention signals, FGE is retained in the ER through PDI interaction, exported via ERGIC-53, and retrieved from post-ER compartments by ERp44, with each interaction serving a distinct functional role in balancing intracellular activation versus paracrine secretion.

    Evidence Co-immunoprecipitation with PDI, ERGIC-53, and ERp44; siRNA knockdown of each interactor with distinct phenotypic outcomes; subcellular fractionation

    PMID:18508857

    Open questions at the time
    • Structural basis of FGE interaction with each ER chaperone not determined
    • How the balance between retention and secretion is physiologically regulated is unknown
    • Whether MSD mutations alter these interactions not tested
  5. 2008 High

    Dissecting multiple MSD mutations revealed that both reduced specific enzymatic activity and decreased protein stability independently contribute to disease, resolving why mutations with similar catalytic impairment can produce different clinical severities.

    Evidence FGE activity assays, protein stability measurements, and ER localization in MSD patient fibroblasts for multiple SUMF1 missense variants

    PMID:18157819

    Open questions at the time
    • Structural mechanism by which individual mutations destabilize FGE not resolved at atomic level
    • Contribution of ER quality control/degradation to residual FGE levels not quantified
  6. 2011 High

    A systematic genotype-phenotype correlation across MSD patients established that the combination of residual FGE activity and protein stability quantitatively predicts clinical severity, from neonatal lethal to mild late-onset forms.

    Evidence Multi-parameter functional analysis (FGE expression, stability, activity, sulfatase activities) across 10 MSD patients with clinical correlation

    PMID:21224894

    Open questions at the time
    • Modifier genes or environmental factors influencing MSD severity not addressed
    • Whether pharmacological stabilization of mutant FGE could be therapeutic remains untested
  7. 2019 Medium

    The copper dependence of FGE catalysis was established, placing it in the class of copper-dependent oxidases and enabling biotechnological exploitation of formylglycine as a site-specific bioconjugation handle.

    Evidence In vitro and mammalian cell reconstitution of copper-dependent FGE-mediated fGly generation; application to antibody-drug conjugate production

    PMID:31161504

    Open questions at the time
    • How copper loading of FGE is regulated in the ER lumen not determined
    • Whether copper availability limits FGE activity in disease states unknown

Open questions

Synthesis pass · forward-looking unresolved questions
  • Key unresolved questions include the structural basis for FGE substrate recognition across diverse sulfatases, how copper is delivered to FGE in the ER, the function of paralog SUMF2 and its relationship to SUMF1, and whether pharmacological stabilization of mutant FGE proteins is a viable therapeutic strategy for MSD.
  • No high-resolution structure of FGE-sulfatase complex
  • SUMF2 function remains uncharacterized
  • No pharmacological chaperone strategy validated for MSD

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0140096 catalytic activity, acting on a protein 3 GO:0016491 oxidoreductase activity 2
Localization
GO:0005783 endoplasmic reticulum 4 GO:0005576 extracellular region 1
Pathway
R-HSA-392499 Metabolism of proteins 3 R-HSA-9609507 Protein localization 1
Partners
ERGIC-53ERP44PDI

Evidence

Reading pass · 13 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2003 SUMF1 encodes the Cα-formylglycine (FGly)-generating enzyme (FGE), which post-translationally converts a conserved cysteine residue in the active site of all sulfatases to FGly, an essential catalytic residue required for sulfatase activity. SUMF1 defines a new gene family conserved from prokaryotes to eukaryotes, with orthologs in vertebrates and a paralog SUMF2 of unknown function. Bioinformatic/phylogenetic analysis of gene family; biochemical identification of FGE as product of SUMF1 Gene High 14563551
2004 SUMF1/FGE strongly enhances the activity of co-expressed sulfatases in COS-7 cells; missense mutations in SUMF1 that cause multiple sulfatase deficiency (MSD) result in severely impaired sulfatase-enhancing activity, with some mutations showing variable effects across different sulfatases. Transient co-expression of SUMF1 mutants with individual sulfatases in COS-7 cells; enzymatic activity assays Human mutation High 15146462
2007 SUMF1 co-expression with sulfatase genes (via AAV or lentiviral vectors) enhances sulfatase activity and improves clearance of intracellular glycosaminoglycan or sulfolipid accumulation in cells from patients with five different sulfatase deficiencies (MLD, CDPX, MPS II, IIIA, VI), and in vivo in MPS-IIIA mouse muscle. AAV/lentivirus-mediated co-delivery in patient cells and mouse models; enzymatic activity assays; biochemical storage clearance assays The Biochemical journal High 17206939
2007 Co-delivery of SUMF1 with SGSH (sulfamidase) via AAV2/5 into the brains of MPS-IIIA mice results in synergistic increases in SGSH activity, visible reduction in lysosomal storage and inflammatory markers, and improvement in motor and cognitive functions, demonstrating SUMF1's enhancing role in the CNS context. Intraventricular AAV2/5 injection in neonatal MPS-IIIA mice; enzymatic activity assays in brain regions; histological storage markers; behavioral testing Human molecular genetics High 17725987
2007 MSD is caused by hypomorphic SUMF1 mutations; all known MSD-causing SUMF1 missense mutant proteins are properly localized to the ER and of correct molecular weight, but provide only partial rescue of sulfatase activities when expressed in Sumf1 knockout MEFs. Complete loss of SUMF1 function is likely lethal in humans. Viral-mediated expression of SUMF1 mutants in Sumf1-/- MEFs; subcellular localization; enzymatic activity rescue assays Human mutation High 17657823
2008 SUMF1 is largely retained in the ER (despite lacking canonical retention signals) where it activates nascent sulfatases, and part of SUMF1 is secreted and taken up paracrinally. SUMF1 physically interacts with PDI, ERGIC-53, and ERp44: PDI couples SUMF1 ER retention and activation; ERGIC-53 favors SUMF1 export from the ER; ERp44 retrieves SUMF1 to the ER. Silencing ERGIC-53 causes proteasomal degradation of SUMF1; down-regulating ERp44 promotes SUMF1 secretion. Co-immunoprecipitation, subcellular fractionation/localization, siRNA knockdown of interactors, functional sulfatase activation assays, proteasome inhibitor experiments Human molecular genetics High 18508857
2008 SUMF1 missense mutations (p.A177P, p.W179S, p.A279V, p.R349W) do not affect ER localization of FGE but decrease specific enzymatic activity to <1–23% of wild type, and variably decrease protein stability; both reduced enzyme activity and reduced protein stability contribute to MSD clinical severity. Subcellular localization in MSD fibroblasts; FGE enzymatic activity assays; protein stability/western blot analysis Human mutation High 18157819
2011 Clinical phenotypic severity in MSD patients correlates with both residual FGE enzymatic activity and FGE protein stability: near-complete loss of FGE activity with highly unstable protein causes neonatal severe phenotype, while high residual activity with unstable protein causes mild phenotype. FGE expression, localization, and stability analysis (western blot, immunofluorescence) in patient-derived cells; FGE activity assays; sulfatase activity measurements; clinical correlation European journal of human genetics : EJHG High 21224894
2019 FGE (encoded by SUMF1) is a copper-dependent post-translational protein modifier that generates formylglycine (an aldehyde-containing amino acid) at a specific cysteine in sulfatase active sites; this formylglycine residue is essential for sulfate ester hydrolysis and can serve as a bioconjugation handle in mammalian expression systems. In vitro and mammalian cell reconstitution of FGE-mediated fGly generation; biochemical characterization; application to antibody-drug conjugate production Methods in molecular biology (Clifton, N.J.) Medium 31161504
2020 A novel SUMF1 missense variant (p.A348V) produces a highly unstable FGE protein that lacks catalytic function, causing a neonatal severe form of MSD; functional analysis in cell culture confirmed loss of FGE activity. Expression of SUMF1 variant in cell culture model; FGE protein stability and activity assays; genotype-phenotype correlation Molecular genetics & genomic medicine Medium 32048457
2017 A novel SUMF1 variant (p.E113K) correctly localizes to the ER but is retained intracellularly and exhibits only ~15% of wild-type FGE activity when expressed in immortalized MSD cells; structural modeling predicts destabilization of secondary structure affecting disulfide bridging and the active site groove. Cell culture expression of FGE variant; subcellular localization; FGE activity assay (steroid sulfatase activation); structural analysis based on crystal structure Molecular genetics and metabolism Medium 28566233
2024 SUMF1 (FGE) does not contain ER retention sequences and relies on ERp44 engagement for proper inter-compartmental distribution in the early secretory pathway, placing it in the same regulatory class as Ero1α, Ero1β, Prx4, and ERAP1. Biochemical interaction analysis in ER pathway context; comparison to known ERp44 clients bioRxivpreprint Low
2025 In zebrafish, sumf1 (ortholog of human SUMF1) acts as a positive regulator of sulfatase activity; sumf1 and sumf2 expression levels invert at gastrulation onset, predicting a reduction in sulfatase activity. Overexpressing sumf1 delays convergence and extension (C&E) onset, while loss of sumf1 function causes precocious C&E. The effector is Sulf1, an extracellular sulfatase modifying heparan sulfate proteoglycans (HSPGs), and altered HSPG sulfation levels suppress sumf1/sumf2 mutant C&E timing phenotypes. Zebrafish embryonic explants; gain- and loss-of-function experiments (overexpression, morpholino/mutant); genetic epistasis with Sulf1 and HSPG sulfation levels; C&E morphogenesis timing assays bioRxivpreprint Medium

Source papers

Stage 0 corpus · 42 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2014 Intracerebral administration of adeno-associated viral vector serotype rh.10 carrying human SGSH and SUMF1 cDNAs in children with mucopolysaccharidosis type IIIA disease: results of a phase I/II trial. Human gene therapy 205 24524415
2007 Functional correction of CNS lesions in an MPS-IIIA mouse model by intracerebral AAV-mediated delivery of sulfamidase and SUMF1 genes. Human molecular genetics 104 17725987
2007 SUMF1 enhances sulfatase activities in vivo in five sulfatase deficiencies. The Biochemical journal 65 17206939
2004 Molecular and functional analysis of SUMF1 mutations in multiple sulfatase deficiency. Human mutation 59 15146462
2003 The human SUMF1 gene, required for posttranslational sulfatase modification, defines a new gene family which is conserved from pro- to eukaryotes. Gene 59 14563551
2008 Multistep, sequential control of the trafficking and function of the multiple sulfatase deficiency gene product, SUMF1 by PDI, ERGIC-53 and ERp44. Human molecular genetics 58 18508857
2011 SUMF1 mutations affecting stability and activity of formylglycine generating enzyme predict clinical outcome in multiple sulfatase deficiency. European journal of human genetics : EJHG 52 21224894
2008 Molecular analysis of SUMF1 mutations: stability and residual activity of mutant formylglycine-generating enzyme determine disease severity in multiple sulfatase deficiency. Human mutation 35 18157819
2007 Multiple sulfatase deficiency is due to hypomorphic mutations of the SUMF1 gene. Human mutation 35 17657823
2015 Natural disease history and characterisation of SUMF1 molecular defects in ten unrelated patients with multiple sulfatase deficiency. Orphanet journal of rare diseases 29 25885655
2008 Effect of elongation factor 1alpha promoter and SUMF1 over in vitro expression of N-acetylgalactosamine-6-sulfate sulfatase. Molecular biology reports 26 18989752
2017 Sulfatase modifying factor 1 (SUMF1) is associated with Chronic Obstructive Pulmonary Disease. Respiratory research 10 28464818
2019 Scientific Opinion on Flavouring Group Evaluation 210 Revision 3 (FGE.210Rev3): Consideration of genotoxic potential for α,β-unsaturated alicyclic ketones and precursors from chemical subgroup 2.4 of FGE.19. EFSA journal. European Food Safety Authority 9 32626305
2018 Scientific Opinion on Flavouring Group Evaluation 201 Revision 2 (FGE.201Rev2): 2-alkylated, aliphatic, acyclic alpha,beta-unsaturated aldehydes and precursors, with or without additional double-bonds, from chemical subgroup 1.1.2 of FGE.19. EFSA journal. European Food Safety Authority 9 32625708
2017 Expanding the genetic cause of multiple sulfatase deficiency: A novel SUMF1 variant in a patient displaying a severe late infantile form of the disease. Molecular genetics and metabolism 9 28566233
2018 Integrative expression analysis identifies a novel interplay between CFTR and linc-SUMF1-2 that involves CF-associated gene dysregulation. Biochemical and biophysical research communications 8 30598261
2018 Scientific Opinion on Flavouring Group Evaluation 203, Revision 2 (FGE.203Rev2): α,β-unsaturated aliphatic aldehydes and precursors from chemical subgroup 1.1.4 of FGE.19 with two or more conjugated double-bonds and with or without additional non-conjugated double-bonds. EFSA journal. European Food Safety Authority 8 32625963
2023 Flavouring Group Evaluation 21 Revision 6 (FGE.21Rev6): thiazoles, thiophenes, thiazoline and thienyl derivatives from chemical groups 29 and 30. EFSA journal. European Food Safety Authority 6 36794062
2022 New mouse models with hypomorphic SUMF1 variants mimic attenuated forms of multiple sulfatase deficiency. Journal of inherited metabolic disease 6 36433920
2020 Detection of 2,4-dichlorophenoxyacetic acid herbicide using a FGE-sulfatase based whole-cell Agrobacterium biosensor. Journal of microbiological methods 6 32645339
2017 Scientific Opinion of Flavouring Group Evaluation 410 (FGE.410): 4',5,7-trihydroxyflavanone from chemical group 25 (phenol derivatives containing ring-alkyl, ring-alkoxy, and side-chains with an oxygenated functional group). EFSA journal. European Food Safety Authority 6 32625330
2017 Scientific Opinion on Flavouring Group Evaluation 226 Revision 1 (FGE.226Rev1): consideration of genotoxicity data on one α,β-unsaturated aldehyde from chemical subgroup 1.1.1(b) of FGE.19. EFSA journal. European Food Safety Authority 6 32625501
2019 Scientific Opinion on Flavouring Group Evaluation 208 Revision 3 (FGE.208Rev3): consideration of genotoxicity data on alicyclic aldehydes with α,β-unsaturation in ring/side-chain and precursors from chemical subgroup 2.2 of FGE.19. EFSA journal. European Food Safety Authority 5 32626109
2019 Scientific Opinion on Flavouring Group Evaluation 204 Revision 1 (FGE.204Rev1): consideration of genotoxicity data on representatives for 17 monounsaturated, aliphatic, α,β-unsaturated ketones and precursors from chemical subgroup 1.2.1 of FGE.19. EFSA journal. European Food Safety Authority 5 32626370
2014 Molecular evaluation of a novel missense mutation & an insertional truncating mutation in SUMF1 gene. The Indian journal of medical research 5 25222778
2023 Late infantile form of multiple sulfatase deficiency with a novel missense variant in the SUMF1 gene: case report and review. BMC pediatrics 4 36959582
2019 Site-Specific Labeling of Proteins Using the Formylglycine-Generating Enzyme (FGE). Methods in molecular biology (Clifton, N.J.) 4 31161504
2024 Flavouring group evaluation 419 (FGE.419): 2-methyl-1-(2-(5-(p-tolyl)-1H-imidazol-2-yl)piperidin-1-yl)butan-1-one. EFSA journal. European Food Safety Authority 3 38711805
2023 Flavouring Group Evaluation 217 Revision 3 (FGE.217Rev3): consideration of genotoxic potential for α,β-unsaturated ketones and precursors from chemical subgroup 4.1 of FGE.19: lactones. EFSA journal. European Food Safety Authority 3 37089172
2020 A homozygous missense variant of SUMF1 in the Bedouin population extends the clinical spectrum in ultrarare neonatal multiple sulfatase deficiency. Molecular genetics & genomic medicine 3 32048457
2022 Scientific opinion on Flavouring group evaluation 216 revision 2 (FGE.216Rev2): consideration of the genotoxicity potential of α,β-unsaturated 2-phenyl-2-alkenals from subgroup 3.3 of FGE.19. EFSA journal. European Food Safety Authority 2 35991962
2025 Structure of the T9SS PorKN ring complex reveals conformational plasticity based on the repurposed FGE fold. mBio 1 40772760
2024 SUMF1 overexpression promotes tumorous cell growth and migration and is correlated with the immune status of patients with glioma. Aging 1 38460946
2024 Non-syndromic retinal dystrophy associated with biallelic variation of SUMF1 and reduced leukocyte sulfatase activity. Clinical genetics 1 38863195
2023 Association between SUMF1 polymorphisms and COVID-19 severity. BMC genomic data 1 37344788
2022 Scientific opinion on flavouring group evaluation 415 (FGE.415): (E)-3-benzo[1,3]dioxol-5-yl-N,N-diphenyl-2-propenamide. EFSA journal. European Food Safety Authority 1 35814922
2022 Genetic analysis of a novel SUMF1 variation associated with a late infantile form of multiple sulfatase deficiency. Journal of clinical laboratory analysis 1 36441600
2025 Preclinical use of a clinically-relevant scAAV9/SUMF1 vector for the treatment of multiple sulfatase deficiency. Communications medicine 0 39870870
2025 Flavouring group evaluation 418 (FGE. 418): 3-[3-(2-isopropyl-5-methyl-cyclohexyl)-ureido]-butyric acid ethyl ester. EFSA journal. European Food Safety Authority 0 39896350
2025 SUMF1 Common Variant rs793391 Is Associated with Response to Inhaled Corticosteroids in Patients with COPD. International journal of molecular sciences 0 41155512
2021 Family-based gene-environment interaction using sequence kernel association test (FGE-SKAT) for complex quantitative traits. Scientific reports 0 33795796
2012 Scientific Opinion on Flavouring Group Evaluation 226 (FGE.226): Consideration of genotoxicity data on one α,β-unsaturated aldehyde from chemical subgroup 1.1.1(b) of FGE.19 by EFSA. EFSA journal. European Food Safety Authority 0 42016130