Summary: Golgi residence fits the type-II glycan-processing enzyme.

Reason: The mas-1 mutant glycan study identifies the product as Golgi mannosidase I, and the original mas-1 molecular analysis reports type-II transmembrane protein isoforms. PTN000201534 is therefore a safe Golgi alpha-mannosidase node for the Drosophila IA-related branch.

Summary: Golgi residence fits the type-II glycan-processing enzyme.

Reason: The mas-1 mutant glycan study identifies the product as Golgi mannosidase I, and the original mas-1 molecular analysis reports type-II transmembrane protein isoforms; together they support Golgi membrane association for this glycan-processing enzyme.

Summary: Golgi residence fits the type-II glycan-processing enzyme.

Reason: The mas-1 mutant glycan study identifies the product as Golgi mannosidase I, and the original mas-1 molecular analysis reports type-II transmembrane protein isoforms; together they support Golgi membrane association for this glycan-processing enzyme.

Summary: The enzyme removes alpha-1,2-linked mannose from oligomannosidic N-glycans.

Reason: Recombinant mas-1 is active toward oligomannosidic glycans, and mas-1 deletion causes Man8GlcNAc2 accumulation. Together these support the catalytic annotation on alpha-Man-Ia rather than transfer solely from a GH47 family label. PTN000201533 transfers the shared mannosyl-oligosaccharide 1,2-alpha-mannosidase chemistry, which is retained across ER and Golgi GH47 branches even though the branches differ in compartment and process.

Summary: The enzyme removes alpha-1,2-linked mannose from oligomannosidic N-glycans.

Reason: Recombinant mas-1 is active toward oligomannosidic glycans, and mas-1 deletion causes Man8GlcNAc2 accumulation. Together these support the catalytic annotation on alpha-Man-Ia rather than transfer solely from a GH47 family label.

Summary: The enzyme removes alpha-1,2-linked mannose from oligomannosidic N-glycans.

Reason: Recombinant mas-1 is active toward oligomannosidic glycans, and mas-1 deletion causes Man8GlcNAc2 accumulation. Together these support the catalytic annotation on alpha-Man-Ia rather than transfer solely from a GH47 family label.

Summary: The enzyme removes alpha-1,2-linked mannose from oligomannosidic N-glycans.

Reason: Recombinant mas-1 is active toward oligomannosidic glycans, and mas-1 deletion causes Man8GlcNAc2 accumulation. Together these support the catalytic annotation on alpha-Man-Ia rather than transfer solely from a GH47 family label.

Summary: The enzyme removes alpha-1,2-linked mannose from oligomannosidic N-glycans.

Reason: Recombinant mas-1 is active toward oligomannosidic glycans, and mas-1 deletion causes Man8GlcNAc2 accumulation. Together these support the catalytic annotation on alpha-Man-Ia rather than transfer solely from a GH47 family label.

Summary: Calcium binding is a cofactor feature of the GH47 catalytic apparatus.

Reason: The calcium-dependent GH47 mechanism makes this inferred binding annotation reasonable; it is ancillary to glycan hydrolysis rather than a distinct calcium-signaling function.

Summary: ER residence is over-propagated from the ER mannosidase branch onto a Golgi-branch enzyme.

Reason: The ER IBD sits on the GH47 root node PTN000201533, and all of its seeds come from the ER mannosidase I (SF55 MAN1B1, yeast and Candida MNS1) and MNL2 (SF103) lineages. Drosophila alpha-Man-Ia is in PTHR11742:SF6, together with its paralog alpha-Man-Ic, C. elegans mans-1 and Arabidopsis MNS1. It also descends from PTN000201534, where PAINT separately placed Golgi membrane using the Golgi class I enzymes (Arabidopsis MNS1/MNS2, mouse Man1a1/Man1a2). The fly product is described as Golgi mannosidase I, a type II membrane protein. A type II Golgi enzyme passes through the ER on the way to the Golgi, so transient ER presence is expected, but "is active in ER" is a property of the ER-mannosidase branch. No fly-specific localization study places alpha-Man-Ia activity in the ER. I treat this as compartmental over-propagation from a GH47 ancestor placed too deep for cellular component. The ER assertion is correct for the ER-branch seeds, so I mark it as over-annotated rather than removing it.

Summary: N-glycan mannose trimming specifies the broad carbohydrate process.

Reason: Man8GlcNAc2 accumulation in the mutant identifies a direct glycoprotein-processing role rather than undifferentiated carbohydrate metabolism.

Proposed replacements: Golgi apparatus N-glycan mannose trimming

Summary: The LOPIT endomembrane-system assignment is correct but less specific than the combined evidence.

Reason: The embryo LOPIT organelle-proteomics study places the protein in the endomembrane system. That fits the Golgi glycan-processing role, but the assay cannot tell the ER, Golgi and post-Golgi compartments apart. Taken with the gene-specific type II membrane topology and the Golgi mannosidase I identity, the evidence supports the more specific Golgi membrane term, which the gene already carries through IBA, ISS and IEA rows.

Proposed replacements: Golgi membrane

Summary: Membrane membership is correct but should be refined to Golgi membrane.

Reason: The original mas-1 molecular analysis reports type II transmembrane products, and UniProt places a transmembrane segment at residues 19-39, so membrane association is correct. The term is less specific than the evidence supports, because the protein is a Golgi mannosidase I. The appropriate refinement is Golgi membrane, which the gene already carries through other rows.

Proposed replacements: Golgi membrane

Summary: A dedicated ERAD role is not established for the Golgi-trimming enzyme.

Reason: The ERAD IBD sits on the GH47 root node PTN000201533. Its seeds include ER-branch enzymes (MAN1B1, yeast MNS1 and MNL2, fission yeast SPAC2E1P5.01c) and one Golgi class IA enzyme, human MAN1A1 (SF31). Including MAN1A1 shows that the PAINT curator deliberately extended ERAD participation to Golgi-type class I mannosidases, so the call cannot be dismissed as a simple ER-branch leak. The Drosophila evidence neither supports nor refutes it. The mas-1 studies measured steady-state N-glycan profiles and developmental phenotypes, and none tested degradation of a misfolded glycoprotein. The fly enzyme is also in a different subfamily (SF6) from the MAN1A1 seed. Recombinant activity on oligomannosidic glycans fits the mannose trimming that marks ERAD substrates, but it does not show that the fly enzyme takes part in ERAD. The cached literature does not let me check the MAN1A1 ERAD evidence behind the seed, so I leave this undecided rather than accept or remove it.

Summary: Golgi N-glycan mannose trimming is the direct biological process.

Reason: The mutant glycan profile accumulates an enzyme substrate while retaining compensatory processing routes, establishing a normal contribution to mannose trimming without requiring lethality.