id: P37287
gene_symbol: PIGA
product_type: PROTEIN
status: INITIALIZED
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: PIGA (phosphatidylinositol N-acetylglucosaminyltransferase subunit A)
  is the catalytic subunit of the glycosylphosphatidylinositol-N-acetylglucosaminyltransferase
  (GPI-GnT) complex, which catalyzes the first, committed step of glycosylphosphatidylinositol
  (GPI) anchor biosynthesis. PIGA transfers N-acetylglucosamine (GlcNAc) from UDP-N-acetylglucosamine
  (UDP-GlcNAc) onto phosphatidylinositol (PI) to form GlcNAc-PI (EC 2.4.1.198), a reaction
  occurring on the cytoplasmic face of the endoplasmic reticulum membrane. PIGA is a
  single-pass ER membrane protein with a large cytoplasmic catalytic domain (homologous
  to bacterial GlcNAc transferases, glycosyltransferase group 1 / GT4 family) and a small
  lumenal domain that mediates rough-ER localization. The GPI-GnT complex additionally
  contains PIGC, PIGH, PIGP, PIGQ, PIGY and DPM2, with PIGA as the catalytic component.
  Somatic loss-of-function mutations of the X-linked PIGA gene in hematopoietic stem cells
  cause paroxysmal nocturnal hemoglobinuria (PNH), through loss of GPI-anchored complement
  regulators on blood cells; germline hypomorphic mutations cause X-linked recessive
  multiple congenital anomalies-hypotonia-seizures syndrome 2 (MCAHS2) and related
  neurodevelopmental disorders.
alternative_products:
- name: '1'
  id: P37287-1
- name: '2'
  id: P37287-2
  sequence_note: VSP_001802
- name: '3'
  id: P37287-3
  sequence_note: VSP_043366, VSP_043367
existing_annotations:
- term:
    id: GO:0000506
    label: glycosylphosphatidylinositol-N-acetylglucosaminyltransferase (GPI-GnT)
      complex
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: part_of
  review:
    summary: PIGA is a subunit of the GPI-GnT complex. This phylogenetically inferred
      complex membership is directly supported by experimental studies of the human
      complex and is a core aspect of PIGA biology.
    action: ACCEPT
    reason: PIGA is the catalytic subunit of the GPI-GnT complex, which comprises at
      least PIGA, PIGC, PIGH, PIGP, PIGQ, PIGY and DPM2. The IBA call is corroborated
      by direct experimental identification of the human complex.
    supported_by:
    - reference_id: PMID:8900170
      supporting_text: PIG-A and PIG-H are subunits of the GPI GlcNAc transferase that
        transfers GlcNAc to PI on the cytoplasmic side of the ER.
    - reference_id: PMID:9463366
      supporting_text: four mammalian gene products form a protein complex in the endoplasmic
        reticulum membrane.
- term:
    id: GO:0006506
    label: GPI anchor biosynthetic process
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: PIGA catalyzes the first, committed step of GPI anchor biosynthesis, so
      involvement in the GPI anchor biosynthetic process is a core biological process
      annotation.
    action: ACCEPT
    reason: The catalytic first step (GlcNAc transfer to PI) initiates the GPI biosynthesis
      pathway. This is well established experimentally and consistent with the phylogenetic
      inference.
    supported_by:
    - reference_id: PMID:9463366
      supporting_text: Biosynthesis of glycosylphosphatidylinositol (GPI) is initiated
        by transfer of N-acetylglucosamine (GlcNAc) from UDP-GlcNAc to phosphatidylinositol
        (PI).
- term:
    id: GO:0017176
    label: phosphatidylinositol N-acetylglucosaminyltransferase activity
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: enables
  review:
    summary: This is the exact, correct molecular function of PIGA - the catalytic subunit
      that transfers GlcNAc from UDP-GlcNAc to phosphatidylinositol (EC 2.4.1.198).
    action: ACCEPT
    reason: PIGA is the catalytic component of the GPI-GnT enzyme; this specific transferase
      activity is the core molecular function and is directly supported by biochemistry.
    supported_by:
    - reference_id: PMID:9463366
      supporting_text: The protein complex had GPI-GlcNAc transferase (GPI-GnT) activity
        in vitro.
    - reference_id: PMID:16162815
      supporting_text: binding directly to the catalytic subunit PIG-A.
- term:
    id: GO:0000506
    label: glycosylphosphatidylinositol-N-acetylglucosaminyltransferase (GPI-GnT)
      complex
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: part_of
  review:
    summary: InterPro-based electronic annotation of GPI-GnT complex membership (via
      the PIG-A/GPI3 signature IPR039507). Correct and consistent with experimental data.
    action: ACCEPT
    reason: The IEA mapping from the PIG-A/GPI3 InterPro entry to the GPI-GnT complex
      is biologically correct; PIGA is an experimentally verified complex member.
    supported_by:
    - reference_id: PMID:8900170
      supporting_text: PIG-A and PIG-H are subunits of the GPI GlcNAc transferase that
        transfers GlcNAc to PI on the cytoplasmic side of the ER.
- term:
    id: GO:0006506
    label: GPI anchor biosynthetic process
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: involved_in
  review:
    summary: Electronic (InterPro/UniPathway) annotation to the GPI anchor biosynthetic
      process, matching the experimentally established role of PIGA.
    action: ACCEPT
    reason: The pathway mapping (UPA00196 GPI-anchor biosynthesis) is correct; PIGA initiates
      this pathway.
    supported_by:
    - reference_id: PMID:9463366
      supporting_text: Biosynthesis of glycosylphosphatidylinositol (GPI) is initiated
        by transfer of N-acetylglucosamine (GlcNAc) from UDP-GlcNAc to phosphatidylinositol
        (PI).
- term:
    id: GO:0016757
    label: glycosyltransferase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  review:
    summary: Generic glycosyltransferase activity from the InterPro glycosyltransferase
      family 1 domain (IPR001296). Correct but a broad parent of the specific PIGA activity.
    action: MARK_AS_OVER_ANNOTATED
    reason: This term is a general ancestor of the specific and experimentally supported
      GO:0017176 (phosphatidylinositol N-acetylglucosaminyltransferase activity), which
      is annotated separately. The generic term is not informative for PIGA's core function.
    supported_by:
    - reference_id: PMID:9463366
      supporting_text: The protein complex had GPI-GlcNAc transferase (GPI-GnT) activity
        in vitro.
- term:
    id: GO:0017176
    label: phosphatidylinositol N-acetylglucosaminyltransferase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: enables
  review:
    summary: Electronic annotation of the specific catalytic activity based on the RHEA/EC
      mapping (RHEA:14789, EC 2.4.1.198). This is the correct core molecular function.
    action: ACCEPT
    reason: The EC/RHEA-derived assignment matches the experimentally established catalytic
      activity of PIGA and is the specific, informative molecular function term.
    supported_by:
    - reference_id: PMID:16162815
      supporting_text: Biosynthesis of glycosylphosphatidylinositol (GPI) is initiated
        by an unusually complex GPI-N-acetylglucosaminyltransferase (GPI-GnT) consisting
        of at least six proteins.
    - reference_id: file:human/PIGA/PIGA-uniprot.txt
      supporting_text: "EC=2.4.1.198"
- term:
    id: GO:0030867
    label: rough endoplasmic reticulum membrane
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  review:
    summary: UniProt subcellular-location keyword mapping to rough ER membrane. Correct
      and consistent with experimental localization data.
    action: ACCEPT
    reason: PIGA localizes to the rough ER membrane; this specific location is experimentally
      verified (the small lumenal domain targets it to the rough ER).
    supported_by:
    - reference_id: PMID:8900170
      supporting_text: part of the small lumenal domain of PIG-A plays an essential functional
        role in targeting itself to the rough ER.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:10944123
  qualifier: enables
  review:
    summary: IntAct-curated binary interactions of PIGA with GPI-GnT complex components
      (DPM2/O94777, PIGP/P57054, PIGH/Q14442, PIGQ/Q9BRB3). These reflect PIGA's role
      as a scaffolding/catalytic member of the GPI-GnT complex.
    action: MARK_AS_OVER_ANNOTATED
    reason: The generic 'protein binding' term is uninformative. The underlying interactions
      are real and are the physical basis of the GPI-GnT complex, which is captured by
      the specific GO:0000506 (GPI-GnT complex) annotation. Per curation guidelines the
      bare protein binding IPI is not retained as a core function.
    supported_by:
    - reference_id: PMID:10944123
      supporting_text: PIG-P, a 134-amino acid protein having two hydrophobic domains,
        associates with PIG-A and GPI1.
    - reference_id: PMID:10944123
      supporting_text: DPM2, but not two other components of dolichol-phosphate-mannose
        synthase, associates with GPI-GnT through interactions with PIG-A, PIG-C and GPI1.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:16162815
  qualifier: enables
  review:
    summary: IntAct-curated interactions of PIGA with GPI-GnT complex components including
      the directly associated regulatory subunit PIGY (Q3MUY2), plus DPM2, PIGP, PIGH,
      PIGQ. Real interactions underpinning complex assembly.
    action: MARK_AS_OVER_ANNOTATED
    reason: Bare 'protein binding' is uninformative and is subsumed by the specific GPI-GnT
      complex (GO:0000506) annotation. The interactions themselves are genuine.
    supported_by:
    - reference_id: PMID:16162815
      supporting_text: PIG-Y appeared to be directly associated with PIG-A.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:33961781
  qualifier: enables
  review:
    summary: High-throughput BioPlex 3.0 AP-MS interactions of PIGA (recovering PIGP and
      PIGH). Consistent with GPI-GnT complex membership but low information content.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic 'protein binding' from a proteome-scale AP-MS screen; not a core function
      term. The recovered partners are GPI-GnT complex members captured by GO:0000506.
    supported_by:
    - reference_id: PMID:33961781
      supporting_text: BioPlex suggests function, localization, and complex membership
        for thousands of proteins.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:8900170
  qualifier: enables
  review:
    summary: IntAct-curated interaction of PIGA with PIGH (Q14442), the earliest characterized
      binary interaction within the GPI-GnT complex.
    action: MARK_AS_OVER_ANNOTATED
    reason: The PIGA-PIGH interaction is real and foundational to the complex, but the
      generic 'protein binding' term is uninformative and is captured by the specific
      GPI-GnT complex (GO:0000506) annotation.
    supported_by:
    - reference_id: PMID:8900170
      supporting_text: they form a protein complex.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:9463366
  qualifier: enables
  review:
    summary: IntAct-curated interaction of PIGA with PIGQ/GPI1 (Q9BRB3), a component of
      the four-subunit GPI-GnT complex characterized in this study.
    action: MARK_AS_OVER_ANNOTATED
    reason: Real interaction within the GPI-GnT complex, but the generic 'protein binding'
      term is uninformative and subsumed by GO:0000506 (GPI-GnT complex).
    supported_by:
    - reference_id: PMID:9463366
      supporting_text: four mammalian gene products form a protein complex in the endoplasmic
        reticulum membrane.
- term:
    id: GO:0006506
    label: GPI anchor biosynthetic process
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-162710
  qualifier: involved_in
  review:
    summary: Reactome traceable-author-statement placing PIGA in the GPI synthesis pathway.
      Matches PIGA's established role initiating GPI anchor biosynthesis.
    action: ACCEPT
    reason: PIGA catalyzes the first reaction of GPI anchor biosynthesis; the Reactome
      pathway assignment is correct and core.
    supported_by:
    - reference_id: PMID:9463366
      supporting_text: Biosynthesis of glycosylphosphatidylinositol (GPI) is initiated
        by transfer of N-acetylglucosamine (GlcNAc) from UDP-GlcNAc to phosphatidylinositol
        (PI).
- term:
    id: GO:0030867
    label: rough endoplasmic reticulum membrane
  evidence_type: EXP
  original_reference_id: PMID:8900170
  qualifier: located_in
  review:
    summary: Experimental demonstration that PIGA is an ER transmembrane protein localizing
      to the rough ER, with its small lumenal domain required for rough-ER targeting.
    action: ACCEPT
    reason: Directly supported by experimental localization/topology work; the rough ER
      membrane is a verified, specific location for PIGA.
    supported_by:
    - reference_id: PMID:8900170
      supporting_text: PIG-A is an ER transmembrane protein with a large cytoplasmic domain
        that has homology to a bacterial GlcNAc transferase and a small lumenal domain.
    - reference_id: PMID:8900170
      supporting_text: part of the small lumenal domain of PIG-A plays an essential functional
        role in targeting itself to the rough ER.
- term:
    id: GO:0000506
    label: glycosylphosphatidylinositol-N-acetylglucosaminyltransferase (GPI-GnT)
      complex
  evidence_type: IPI
  original_reference_id: PMID:16162815
  qualifier: part_of
  review:
    summary: ComplexPortal (CPX-6502) assertion of PIGA as part of the GPI-GnT complex,
      based on the study identifying the seven-component complex including PIGY.
    action: ACCEPT
    reason: PIGA is an experimentally established member (catalytic subunit) of the GPI-GnT
      complex; complex membership is a core annotation.
    supported_by:
    - reference_id: PMID:16162815
      supporting_text: Biosynthesis of glycosylphosphatidylinositol (GPI) is initiated
        by an unusually complex GPI-N-acetylglucosaminyltransferase (GPI-GnT) consisting
        of at least six proteins.
- term:
    id: GO:0005789
    label: endoplasmic reticulum membrane
  evidence_type: IDA
  original_reference_id: PMID:16162815
  qualifier: located_in
  review:
    summary: Direct-assay localization of PIGA to the ER membrane, where the GPI-GnT complex
      assembles and functions.
    action: ACCEPT
    reason: The ER membrane is the verified site of PIGA action and GPI-GnT complex assembly;
      this is a core cellular component annotation.
    supported_by:
    - reference_id: PMID:9463366
      supporting_text: four mammalian gene products form a protein complex in the endoplasmic
        reticulum membrane.
- term:
    id: GO:0008194
    label: UDP-glycosyltransferase activity
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-162730
  qualifier: enables
  review:
    summary: Reactome describes the reaction as using the UDP-sugar donor UDP-GlcNAc. The
      term correctly captures the UDP-sugar donor class but is less specific than the exact
      enzyme activity.
    action: MODIFY
    reason: UDP-glycosyltransferase activity is a broad donor-class term. The specific,
      experimentally supported activity is phosphatidylinositol N-acetylglucosaminyltransferase
      activity (GO:0017176, EC 2.4.1.198), which uses UDP-GlcNAc as donor and PI as acceptor.
    proposed_replacement_terms:
    - id: GO:0017176
      label: phosphatidylinositol N-acetylglucosaminyltransferase activity
    supported_by:
    - reference_id: PMID:9463366
      supporting_text: Biosynthesis of glycosylphosphatidylinositol (GPI) is initiated
        by transfer of N-acetylglucosamine (GlcNAc) from UDP-GlcNAc to phosphatidylinositol
        (PI).
- term:
    id: GO:0016020
    label: membrane
  evidence_type: HDA
  original_reference_id: PMID:19946888
  qualifier: located_in
  review:
    summary: High-throughput identification of PIGA in an NK-cell membrane proteome. Only
      confirms membrane association without specifying the organelle.
    action: MARK_AS_OVER_ANNOTATED
    reason: The 'membrane' term is a very general location from a proteome-scale study;
      PIGA's informative location is the ER membrane (GO:0005789 / GO:0030867), which is
      annotated separately with direct evidence.
    supported_by:
    - reference_id: PMID:19946888
      supporting_text: approximately 40% of the identified proteins were predicted as plausible
        membrane proteins.
- term:
    id: GO:0005789
    label: endoplasmic reticulum membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-162730
  qualifier: located_in
  review:
    summary: Reactome traceable-author-statement placing the GlcNAc-PI synthesis reaction
      (and PIGA) at the ER membrane. Consistent with direct experimental data.
    action: ACCEPT
    reason: The ER membrane is the verified site of the PIGA-catalyzed reaction; a core
      cellular component annotation.
    supported_by:
    - reference_id: PMID:8900170
      supporting_text: PIG-A is an ER transmembrane protein with a large cytoplasmic domain
        that has homology to a bacterial GlcNAc transferase and a small lumenal domain.
- term:
    id: GO:0000506
    label: glycosylphosphatidylinositol-N-acetylglucosaminyltransferase (GPI-GnT)
      complex
  evidence_type: IDA
  original_reference_id: PMID:16162815
  qualifier: part_of
  review:
    summary: Direct-assay identification of PIGA as a component of the seven-subunit GPI-GnT
      complex (adding PIGY as the seventh component directly associated with PIGA).
    action: ACCEPT
    reason: Experimentally established core complex membership; PIGA is the catalytic subunit.
    supported_by:
    - reference_id: PMID:16162815
      supporting_text: PIG-Y appeared to be directly associated with PIG-A.
- term:
    id: GO:0017176
    label: phosphatidylinositol N-acetylglucosaminyltransferase activity
  evidence_type: TAS
  original_reference_id: PMID:16162815
  qualifier: enables
  review:
    summary: Traceable-author-statement of PIGA's phosphatidylinositol N-acetylglucosaminyltransferase
      activity, from the study establishing catalytic activity and the seven-component complex.
    action: ACCEPT
    reason: This is the specific, experimentally supported core molecular function of PIGA
      (catalytic subunit; EC 2.4.1.198).
    supported_by:
    - reference_id: PMID:16162815
      supporting_text: Biosynthesis of glycosylphosphatidylinositol (GPI) is initiated
        by an unusually complex GPI-N-acetylglucosaminyltransferase (GPI-GnT) consisting
        of at least six proteins.
core_functions:
- description: Catalytic subunit of the GPI-GnT complex that transfers N-acetylglucosamine
    from UDP-GlcNAc to phosphatidylinositol (EC 2.4.1.198), catalyzing the first committed
    step of GPI anchor biosynthesis at the ER membrane.
  molecular_function:
    id: GO:0017176
    label: phosphatidylinositol N-acetylglucosaminyltransferase activity
  directly_involved_in:
  - id: GO:0006506
    label: GPI anchor biosynthetic process
  locations:
  - id: GO:0005789
    label: endoplasmic reticulum membrane
  in_complex:
    id: GO:0000506
    label: glycosylphosphatidylinositol-N-acetylglucosaminyltransferase (GPI-GnT)
      complex
  supported_by:
  - reference_id: PMID:16162815
    supporting_text: Biosynthesis of glycosylphosphatidylinositol (GPI) is initiated
      by an unusually complex GPI-N-acetylglucosaminyltransferase (GPI-GnT) consisting
      of at least six proteins.
  - reference_id: PMID:9463366
    supporting_text: The protein complex had GPI-GlcNAc transferase (GPI-GnT) activity
      in vitro.
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO
    terms
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF: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:0000120
  title: Combined Automated Annotation using Multiple IEA Methods
  findings: []
- id: PMID:10944123
  title: Initial enzyme for glycosylphosphatidylinositol biosynthesis requires PIG-P
    and is regulated by DPM2.
  findings:
  - statement: "GPI-GnT requires PIG-P as an essential component and is regulated by DPM2, which associates with the complex through interactions with PIG-A, PIG-C and GPI1 and enhances enzyme activity ~3-fold."
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: PubMed-verified. Establishes PIG-P and DPM2 as components/regulator of
      the PIGA-containing GPI-GnT complex; supports the protein-binding IPI to DPM2/PIGP.
- id: PMID:16162815
  title: The initial enzyme for glycosylphosphatidylinositol biosynthesis requires
    PIG-Y, a seventh component.
  findings:
  - statement: "PIGA is the catalytic subunit of the GPI-GnT complex; PIG-Y is directly associated with PIG-A and regulates GPI-GnT activity. This study established the catalytic activity and seven-component complex (EC 2.4.1.198)."
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: PubMed-verified. Primary source for PIGA catalytic-subunit function,
      EC 2.4.1.198, and the seven-component GPI-GnT complex.
- id: PMID:19946888
  title: Defining the membrane proteome of NK cells.
  findings:
  - statement: "High-throughput membrane proteome of the NK-like cell line YTS; supports only a generic membrane localization for PIGA."
    reference_section_type: ABSTRACT
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: PubMed-verified proteomics survey; supports only the general membrane
      annotation, not organelle specificity.
- id: PMID:33961781
  title: Dual proteome-scale networks reveal cell-specific remodeling of the human
    interactome.
  findings:
  - statement: "BioPlex 3.0 AP-MS interactome; recovers PIGA interactions with GPI-GnT complex members (PIGP, PIGH), supporting a generic protein-binding annotation."
    reference_section_type: DISCUSSION
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: PubMed-verified proteome-scale AP-MS; low information content for PIGA's
      specific function beyond complex membership.
- id: PMID:8900170
  title: PIG-A and PIG-H, which participate in glycosylphosphatidylinositol anchor
    biosynthesis, form a protein complex in the endoplasmic reticulum.
  findings:
  - statement: "PIG-A is an ER transmembrane protein with a large cytoplasmic (catalytic) domain and a small lumenal domain that targets it to the rough ER; PIG-A and PIG-H form a complex and transfer GlcNAc to PI on the cytoplasmic side of the ER."
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: PubMed-verified. Primary source for PIGA ER-membrane localization, topology,
      and cytoplasmic-face catalysis.
- id: PMID:9463366
  title: The first step of glycosylphosphatidylinositol biosynthesis is mediated by
    a complex of PIG-A, PIG-H, PIG-C and GPI1.
  findings:
  - statement: "The first step of GPI biosynthesis (GlcNAc transfer from UDP-GlcNAc to PI) is mediated by an ER-membrane complex of PIG-A, PIG-H, PIG-C and GPI1 that has GPI-GnT activity in vitro."
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: PubMed-verified. Establishes the multi-subunit GPI-GnT complex and its
      in vitro GlcNAc-transferase activity.
- id: Reactome:R-HSA-162710
  title: Synthesis of glycosylphosphatidylinositol (GPI)
  findings: []
- id: Reactome:R-HSA-162730
  title: phosphatidylinositol + UDP-N-acetyl-D-glucosamine -> N-acetylglucosaminyl-PI
    + UDP
  findings: []
- id: file:human/PIGA/PIGA-uniprot.txt
  title: UniProtKB P37287 (PIGA_HUMAN) record
  findings:
  - statement: "Catalytic subunit of the GPI-GnT complex that catalyzes transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to phosphatidylinositol (EC 2.4.1.198); rough ER membrane, single-pass membrane protein; complex composed of PIGA, PIGC, PIGH, PIGP, PIGQ, PIGY and DPM2."
    reference_section_type: OTHER
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: UniProt curated record; primary source for EC number, catalytic activity,
      subunit composition, and subcellular location.