id: Q9BV10
gene_symbol: ALG12
product_type: PROTEIN
status: INITIALIZED
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: >-
  ALG12 is an endoplasmic reticulum membrane, ER-lumen-facing
  dolichyl-phosphate-mannose (Dol-P-Man)-dependent alpha-1,6-mannosyltransferase
  (glycosyltransferase family GT22; EC 2.4.1.260) that acts in the biosynthesis
  of the dolichol-linked oligosaccharide (LLO) precursor used for protein
  asparagine (N)-linked glycosylation. In the ER lumen it adds the eighth
  mannose residue in an alpha-1,6 linkage from Dol-P-Man onto
  Man7GlcNAc2-PP-dolichol to produce Man8GlcNAc2-PP-dolichol. It is a
  multi-pass ER membrane protein. Loss of its mannosyltransferase activity
  causes ALG12-CDG (congenital disorder of glycosylation type Ig), a
  multisystem disease with under-glycosylated serum glycoproteins.
existing_annotations:
- term:
    id: GO:0000009
    label: alpha-1,6-mannosyltransferase activity
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: enables
  review:
    summary: >-
      Phylogenetic (IBA) call of alpha-1,6-mannosyltransferase activity. This is
      correct for ALG12, which forms the alpha-1,6 linkage when adding the eighth
      mannose of LLO assembly, though it is a general parent of the specific
      Dol-P-Man-dependent term GO:0052917.
    action: ACCEPT
    reason: >-
      Correct molecular activity, consistent with the experimentally verified
      alpha-1,6-mannosyltransferase function. Retained as an accurate parent of
      the more specific core MF term GO:0052917.
    supported_by:
    - reference_id: PMID:12217961
      supporting_text: >-
        we describe a deficiency in the ALG12 ER
    - reference_id: file:human/ALG12/ALG12-uniprot.txt
      supporting_text: >-
        adds the eighth mannose residue in an alpha-1,6 linkage onto
- term:
    id: GO:0005789
    label: endoplasmic reticulum membrane
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: is_active_in
  review:
    summary: >-
      Phylogenetic (IBA) localization of active ALG12 to the ER membrane. ALG12
      is a multi-pass ER membrane protein whose catalytic site faces the ER
      lumen, consistent with the lumenal LLO mannose additions.
    action: ACCEPT
    reason: >-
      Correct subcellular location; the enzyme is an integral ER membrane protein
      acting on the lumenal LLO intermediate.
    supported_by:
    - reference_id: file:human/ALG12/ALG12-uniprot.txt
      supporting_text: >-
        SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
- term:
    id: GO:0006487
    label: protein N-linked glycosylation
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: >-
      Phylogenetic (IBA) involvement in protein N-linked glycosylation. ALG12
      builds the LLO precursor that is transferred en bloc to asparagine
      residues of nascent proteins, so it is genuinely part of the
      N-glycosylation process.
    action: ACCEPT
    reason: >-
      Core biological process. ALG12 contributes the eighth mannose of the
      dolichol-linked precursor used for protein N-glycosylation.
    supported_by:
    - reference_id: PMID:11983712
      supporting_text: >-
        used for protein N-glycosylation
    - reference_id: PMID:12217961
      supporting_text: >-
        N-linked glycans are first
- term:
    id: GO:0005789
    label: endoplasmic reticulum membrane
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  review:
    summary: >-
      Electronic (UniProt SubCell mapping) location in the ER membrane. Agrees
      with the curated SUBCELLULAR LOCATION and the IBA/TAS ER-membrane calls.
    action: ACCEPT
    reason: >-
      Correct location, consistent with all other evidence for ER membrane
      localization.
    supported_by:
    - reference_id: file:human/ALG12/ALG12-uniprot.txt
      supporting_text: >-
        SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
- term:
    id: GO:0016757
    label: glycosyltransferase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  review:
    summary: >-
      InterPro2GO (IEA) mapping from the GT22/Glyco_transf_22 domain to the broad
      parent term glycosyltransferase activity. Correct but uninformative
      relative to the specific mannosyltransferase terms.
    action: ACCEPT
    reason: >-
      Correct high-level activity inferred from the glycosyltransferase family 22
      domain; acceptable as a broad IEA parent of the specific core MF term.
    supported_by:
    - reference_id: file:human/ALG12/ALG12-uniprot.txt
      supporting_text: >-
        Belongs to the glycosyltransferase 22 family
- term:
    id: GO:0052917
    label: dol-P-Man:Man(7)GlcNAc(2)-PP-Dol alpha-1,6-mannosyltransferase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: enables
  review:
    summary: >-
      Electronic (RHEA/EC 2.4.1.260) mapping to the exact Dol-P-Man-dependent
      alpha-1,6-mannosyltransferase reaction. This is the precise catalytic
      activity of ALG12 and matches the experimentally supported EC.
    action: ACCEPT
    reason: >-
      Exactly correct molecular function; corroborated by the EXP and IMP
      annotations to the same term.
    supported_by:
    - reference_id: PMID:11983712
      supporting_text: >-
        dolichyl-P-Man:Man(7)GlcNAc(2)-PP-dolichyl alpha6-mannosyltransferase that is
    - reference_id: file:human/ALG12/ALG12-uniprot.txt
      supporting_text: >-
        EC=2.4.1.260
- term:
    id: GO:0006488
    label: dolichol-linked oligosaccharide biosynthetic process
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-446193
  qualifier: involved_in
  review:
    summary: >-
      Reactome (TAS) involvement in dolichol-linked oligosaccharide biosynthesis.
      ALG12 catalyzes one step (eighth mannose addition) of LLO assembly, so this
      is a correct and core biological process.
    action: ACCEPT
    reason: >-
      Core biological process, corroborated by the IMP and IDA annotations to the
      same term from CDG-Ig studies.
    supported_by:
    - reference_id: PMID:11983712
      supporting_text: >-
        deficient in their capacity to add the eighth mannose residue onto the
- term:
    id: GO:0052917
    label: dol-P-Man:Man(7)GlcNAc(2)-PP-Dol alpha-1,6-mannosyltransferase activity
  evidence_type: EXP
  original_reference_id: PMID:12217961
  qualifier: enables
  review:
    summary: >-
      Experimental annotation of the specific Dol-P-Man-dependent
      alpha-1,6-mannosyltransferase activity. Patient fibroblasts show a defect in
      the ALG12 alpha-1,6-mannosyltransferase, with yeast alg12 complementation
      confirming the enzymatic identity of the human protein.
    action: ACCEPT
    reason: >-
      Directly experimentally supported core molecular function; the exact current
      GOA MF term for ALG12 (EC 2.4.1.260).
    supported_by:
    - reference_id: PMID:12217961
      supporting_text: >-
        we describe a deficiency in the ALG12 ER
    - reference_id: PMID:12217961
      supporting_text: >-
        the dolichyl pyrophosphate-GlcNAc(2)Man(7)-dependent ALG12 alpha1,6
- term:
    id: GO:0098553
    label: lumenal side of endoplasmic reticulum membrane
  evidence_type: IC
  original_reference_id: PMID:12217961
  qualifier: is_active_in
  review:
    summary: >-
      Curator-inferred (IC) localization of active ALG12 to the lumenal side of
      the ER membrane. The lumenal mannose additions of LLO assembly (using
      Dol-P-Man) occur on the ER lumenal face, consistent with the ER
      alpha-1,6-mannosyltransferase described for ALG12.
    action: ACCEPT
    reason: >-
      Correct and more specific than the generic ER membrane term; reflects the
      lumenal topology of the catalytic activity.
    supported_by:
    - reference_id: PMID:12217961
      supporting_text: >-
        we describe a deficiency in the ALG12 ER
    - reference_id: file:human/ALG12/ALG12-uniprot.txt
      supporting_text: >-
        In the lumen of the endoplasmic reticulum
- term:
    id: GO:0006487
    label: protein N-linked glycosylation
  evidence_type: IMP
  original_reference_id: PMID:11983712
  qualifier: involved_in
  review:
    summary: >-
      Mutant-phenotype (IMP) evidence for involvement in protein N-linked
      glycosylation. CDG-Ig patient fibroblasts with defective ALG12 show
      under-glycosylated glycoproteins, and the phenotype is rescued by wild-type
      ALG12, tying ALG12 function to N-glycosylation.
    action: ACCEPT
    reason: >-
      Experimentally supported core biological process.
    supported_by:
    - reference_id: PMID:11983712
      supporting_text: >-
        under-glycosylated serum glycoproteins
- term:
    id: GO:0006487
    label: protein N-linked glycosylation
  evidence_type: IMP
  original_reference_id: PMID:12093361
  qualifier: involved_in
  review:
    summary: >-
      Independent mutant-phenotype (IMP) evidence for involvement in protein
      N-linked glycosylation. A second CDG-Ig patient with reduced ALG12
      mannosyltransferase activity shows partial loss of N-glycan side chains on
      serum transferrin, rescued by wild-type ALG12.
    action: ACCEPT
    reason: >-
      Experimentally supported core biological process, independently
      corroborating PMID:11983712.
    supported_by:
    - reference_id: PMID:12093361
      supporting_text: >-
        the partial loss of complete N-glycan
- term:
    id: GO:0006488
    label: dolichol-linked oligosaccharide biosynthetic process
  evidence_type: IMP
  original_reference_id: PMID:11983712
  qualifier: involved_in
  review:
    summary: >-
      Mutant-phenotype (IMP) evidence for involvement in dolichol-linked
      oligosaccharide biosynthesis. Loss of ALG12 blocks addition of the eighth
      mannose onto the LLO precursor; wild-type gene transduction normalizes the
      phenotype.
    action: ACCEPT
    reason: >-
      Experimentally supported core biological process (the direct step ALG12
      catalyzes in LLO assembly).
    supported_by:
    - reference_id: PMID:11983712
      supporting_text: >-
        deficient in their capacity to add the eighth mannose residue onto the
- term:
    id: GO:0006488
    label: dolichol-linked oligosaccharide biosynthetic process
  evidence_type: IMP
  original_reference_id: PMID:12093361
  qualifier: involved_in
  review:
    summary: >-
      Independent mutant-phenotype (IMP) evidence for involvement in
      dolichol-linked oligosaccharide biosynthesis. Reduced ALG12 activity causes
      accumulation of the Man7GlcNAc2-PP-Dol intermediate.
    action: ACCEPT
    reason: >-
      Experimentally supported core biological process, corroborating the other
      IMP/IDA annotations.
    supported_by:
    - reference_id: PMID:12093361
      supporting_text: >-
        leading to the accumulation of Man(7)GlcNAc(2)-PP-Dol, which was transferred to
- term:
    id: GO:0052917
    label: dol-P-Man:Man(7)GlcNAc(2)-PP-Dol alpha-1,6-mannosyltransferase activity
  evidence_type: IMP
  original_reference_id: PMID:11983712
  qualifier: enables
  review:
    summary: >-
      Mutant-phenotype (IMP) evidence for the specific Dol-P-Man-dependent
      alpha-1,6-mannosyltransferase activity. The CDG-Ig patient's fibroblasts
      cannot add the eighth mannose, and the human ALG12 cDNA rescues the defect,
      identifying ALG12 as this enzyme.
    action: ACCEPT
    reason: >-
      Experimentally supported core molecular function; the exact current GOA MF
      term for ALG12.
    supported_by:
    - reference_id: PMID:11983712
      supporting_text: >-
        dolichyl-P-Man:Man(7)GlcNAc(2)-PP-dolichyl alpha6-mannosyltransferase that is
- term:
    id: GO:0052917
    label: dol-P-Man:Man(7)GlcNAc(2)-PP-Dol alpha-1,6-mannosyltransferase activity
  evidence_type: IMP
  original_reference_id: PMID:12093361
  qualifier: enables
  review:
    summary: >-
      Independent mutant-phenotype (IMP) evidence for the Dol-P-Man-dependent
      mannosyltransferase activity. Patient fibroblasts show severely reduced
      Dol-P-Man:Man7GlcNAc2-PP-Dol mannosyltransferase activity, normalized by
      wild-type ALG12 expression.
    action: ACCEPT
    reason: >-
      Experimentally supported core molecular function, independently
      corroborating PMID:11983712.
    supported_by:
    - reference_id: PMID:12093361
      supporting_text: >-
        Retroviral expression of the wild-type
- term:
    id: GO:0000030
    label: mannosyltransferase activity
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-446198
  qualifier: enables
  review:
    summary: >-
      Reactome (TAS) mannosyltransferase activity. Correct but overly general:
      the specific and experimentally supported activity is the Dol-P-Man-dependent
      alpha-1,6-mannosyltransferase GO:0052917.
    action: MODIFY
    reason: >-
      Too general. ALG12's activity is captured precisely by GO:0052917; replace
      the generic mannosyltransferase term with the specific one.
    proposed_replacement_terms:
    - id: GO:0052917
      label: dol-P-Man:Man(7)GlcNAc(2)-PP-Dol alpha-1,6-mannosyltransferase activity
    supported_by:
    - reference_id: PMID:11983712
      supporting_text: >-
        dolichyl-P-Man:Man(7)GlcNAc(2)-PP-dolichyl alpha6-mannosyltransferase that is
- term:
    id: GO:0000030
    label: mannosyltransferase activity
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-4720497
  qualifier: enables
  review:
    summary: >-
      Reactome (TAS) mannosyltransferase activity (from the defective-ALG12
      disease reaction). Same over-general term as R-HSA-446198.
    action: MODIFY
    reason: >-
      Too general; the specific activity term GO:0052917 should be used.
    proposed_replacement_terms:
    - id: GO:0052917
      label: dol-P-Man:Man(7)GlcNAc(2)-PP-Dol alpha-1,6-mannosyltransferase activity
    supported_by:
    - reference_id: PMID:11983712
      supporting_text: >-
        dolichyl-P-Man:Man(7)GlcNAc(2)-PP-dolichyl alpha6-mannosyltransferase that is
- term:
    id: GO:0005789
    label: endoplasmic reticulum membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-4720497
  qualifier: located_in
  review:
    summary: >-
      Reactome (TAS) location in the ER membrane. Consistent with all other
      ER-membrane evidence.
    action: ACCEPT
    reason: >-
      Correct subcellular location.
    supported_by:
    - reference_id: file:human/ALG12/ALG12-uniprot.txt
      supporting_text: >-
        SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
- term:
    id: GO:0016020
    label: membrane
  evidence_type: HDA
  original_reference_id: PMID:19946888
  qualifier: located_in
  review:
    summary: >-
      High-throughput proteomics (HDA) detection of ALG12 in a membrane fraction
      from an NK-like cell line. The generic "membrane" term adds no information
      beyond the specific ER membrane localization.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Uninformative generic membrane term from a large-scale membrane-proteome
      survey (1843 proteins); the specific, well-supported location is ER
      membrane. Not incorrect, but over-broad and non-core.
    supported_by:
    - reference_id: PMID:19946888
      supporting_text: >-
        identified 1843 proteins with high confidence scores
- term:
    id: GO:0006488
    label: dolichol-linked oligosaccharide biosynthetic process
  evidence_type: IDA
  original_reference_id: PMID:11983712
  qualifier: acts_upstream_of_or_within
  review:
    summary: >-
      Direct-assay (IDA) evidence that ALG12 acts within dolichol-linked
      oligosaccharide biosynthesis, with the acts_upstream_of_or_within
      qualifier. The eighth mannose addition step ALG12 catalyzes is directly
      demonstrated by the biochemical defect and its rescue.
    action: ACCEPT
    reason: >-
      Experimentally supported core biological process.
    supported_by:
    - reference_id: PMID:11983712
      supporting_text: >-
        deficient in their capacity to add the eighth mannose residue onto the
- term:
    id: GO:0005789
    label: endoplasmic reticulum membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-446198
  qualifier: located_in
  review:
    summary: >-
      Reactome (TAS) location in the ER membrane. Consistent with all other
      ER-membrane evidence.
    action: ACCEPT
    reason: >-
      Correct subcellular location.
    supported_by:
    - reference_id: file:human/ALG12/ALG12-uniprot.txt
      supporting_text: >-
        SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
- term:
    id: GO:0005783
    label: endoplasmic reticulum
  evidence_type: NAS
  original_reference_id: PMID:12217961
  qualifier: located_in
  review:
    summary: >-
      Non-traceable author statement (NAS) placing ALG12 in the endoplasmic
      reticulum. Broader than the ER membrane term but correct; ALG12 is an ER
      alpha-1,6-mannosyltransferase.
    action: ACCEPT
    reason: >-
      Correct but less specific than the ER membrane annotations; retained as an
      accurate broader location.
    supported_by:
    - reference_id: PMID:12217961
      supporting_text: >-
        we describe a deficiency in the ALG12 ER
- term:
    id: GO:0006457
    label: protein folding
  evidence_type: NAS
  original_reference_id: PMID:12217961
  qualifier: involved_in
  review:
    summary: >-
      Non-traceable author statement (NAS) associating ALG12 with protein
      folding. ALG12 is a mannosyltransferase that builds the N-glycan precursor;
      N-glycosylation supports downstream glycoprotein folding/quality control,
      but ALG12 does not itself carry out protein folding. This mislabels the
      molecular role.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Over-annotation via a downstream/indirect consequence. ALG12's direct role
      is dolichol-linked oligosaccharide biosynthesis for N-glycosylation
      (GO:0006488, GO:0006487); "protein folding" is an indirect effect and does
      not describe ALG12's function. Non-core.
    supported_by:
    - reference_id: PMID:12217961
      supporting_text: >-
        N-linked glycans are first
core_functions:
- description: >-
    Dol-P-Man-dependent alpha-1,6-mannosyltransferase that adds the eighth
    mannose from dolichyl-phosphate-mannose in an alpha-1,6 linkage onto
    Man7GlcNAc2-PP-dolichol to produce Man8GlcNAc2-PP-dolichol in the ER lumen
    (EC 2.4.1.260).
  molecular_function:
    id: GO:0052917
    label: dol-P-Man:Man(7)GlcNAc(2)-PP-Dol alpha-1,6-mannosyltransferase activity
  directly_involved_in:
  - id: GO:0006488
    label: dolichol-linked oligosaccharide biosynthetic process
  locations:
  - id: GO:0005789
    label: endoplasmic reticulum membrane
  supported_by:
  - reference_id: PMID:11983712
    supporting_text: >-
      dolichyl-P-Man:Man(7)GlcNAc(2)-PP-dolichyl alpha6-mannosyltransferase that is
  - reference_id: PMID:11983712
    supporting_text: >-
      deficient in their capacity to add the eighth mannose residue onto the
- description: >-
    ER membrane mannosyltransferase that contributes the eighth mannose of the
    dolichol-linked oligosaccharide precursor transferred en bloc to asparagine
    residues during protein N-linked glycosylation.
  molecular_function:
    id: GO:0052917
    label: dol-P-Man:Man(7)GlcNAc(2)-PP-Dol alpha-1,6-mannosyltransferase activity
  directly_involved_in:
  - id: GO:0006487
    label: protein N-linked glycosylation
  locations:
  - id: GO:0005789
    label: endoplasmic reticulum membrane
  supported_by:
  - reference_id: PMID:12093361
    supporting_text: >-
      Deficiency of the endoplasmic reticulum enzyme dolichyl-phosphate mannose
  - reference_id: PMID:12093361
    supporting_text: >-
      the partial loss of complete N-glycan
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:11983712
  title: Congenital disorders of glycosylation type Ig is defined by a deficiency
    in dolichyl-P-mannose:Man7GlcNAc2-PP-dolichyl mannosyltransferase.
  findings:
  - statement: >-
      Human ALG12, the ortholog of yeast ALG12, encodes the
      dolichyl-P-Man:Man7GlcNAc2-PP-dolichyl alpha6-mannosyltransferase; CDG-Ig
      patient fibroblasts are deficient in adding the eighth mannose onto the LLO
      precursor, and the defect (F142V) is rescued by wild-type ALG12.
    supporting_text: >-
      deficient in their capacity to add the eighth mannose residue onto the
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      PubMed-verified; primary paper establishing human ALG12 identity, the
      Dol-P-Man-dependent alpha-1,6-mannosyltransferase activity, LLO
      biosynthesis role, and CDG-Ig disease. Abstract-only in cache.
- id: PMID:12093361
  title: Deficiency of dolichyl-P-Man:Man7GlcNAc2-PP-dolichyl mannosyltransferase
    causes congenital disorder of glycosylation type Ig.
  findings:
  - statement: >-
      A second CDG-Ig patient shows severely reduced ER Dol-P-Man:Man7GlcNAc2-PP-Dol
      mannosyltransferase activity with accumulation of Man7GlcNAc2-PP-Dol and
      partial loss of N-glycan side chains; wild-type ALG12 normalizes activity.
    supporting_text: >-
      leading to the accumulation of Man(7)GlcNAc(2)-PP-Dol, which was transferred to
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      PubMed-verified; independent confirmation of ALG12 mannosyltransferase
      activity, LLO role, and CDG-Ig. Abstract-only in cache.
- id: PMID:12217961
  title: ALG12 mannosyltransferase defect in congenital disorder of glycosylation
    type lg.
  findings:
  - statement: >-
      Describes deficiency in the ALG12 ER alpha-1,6-mannosyltransferase; ER
      lumenal LLO context; yeast alg12 complementation confirms enzyme identity;
      defines CDG-Ig.
    supporting_text: >-
      we describe a deficiency in the ALG12 ER
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      PubMed-verified; supports ER localization, lumenal topology, and the
      alpha-1,6-mannosyltransferase activity. Abstract-only in cache.
- id: PMID:19946888
  title: Defining the membrane proteome of NK cells.
  findings:
  - statement: >-
      Large-scale membrane-proteome survey of an NK-like cell line detecting
      ALG12 among 1843 proteins; basis of the generic membrane annotation only.
    supporting_text: >-
      identified 1843 proteins with high confidence scores
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: >-
      PubMed-verified; high-throughput proteomics providing only generic membrane
      localization, not gene-specific function.
- id: Reactome:R-HSA-446193
  title: Biosynthesis of the N-glycan precursor (dolichol lipid-linked oligosaccharide,
    LLO) and transfer to a nascent protein
  findings: []
- id: Reactome:R-HSA-446198
  title: ALG12 transfers Man to N-glycan precursor (GlcNAc)2 (Man)7 (PP-Dol)1
  findings: []
- id: Reactome:R-HSA-4720497
  title: Defective ALG12 does not add mannose to the N-glycan precursor
  findings: []
- id: file:human/ALG12/ALG12-uniprot.txt
  title: UniProtKB Q9BV10 (ALG12_HUMAN) curated entry
  findings:
  - statement: >-
      ALG12 is an ER membrane, multi-pass Dol-P-Man-dependent
      alpha-1,6-mannosyltransferase (EC 2.4.1.260) of the glycosyltransferase 22
      family that adds the eighth mannose onto Man7GlcNAc2-PP-dolichol in the ER
      lumen; defects cause CDG type Ig.
    supporting_text: >-
      adds the eighth mannose residue in an alpha-1,6 linkage onto