DDC

Summary: Retain the phylogenetically grounded AADC activity.

Reason: The human 480-residue sequence lies below the experimentally grounded PTN000242975 assertion in PTHR11999. Experimental descendant evidence supports the enzyme class, including human target evidence; the target appearing among the descendants is legitimate grounding, not circularity. Human activity assays and the conserved PLP-dependent chemistry support this source-level assertion. The two substrate-specific core units summarize its physiology without invalidating the broad enzyme-class annotation.

Summary: Retain the localization evidence at the existing cytosol level.

Reason: The cytoplasm assertion at PTN007556042 is inherited by human DDC and is biologically consistent with its soluble catalytic function. Existing cytosol annotations from both DDC reactions are more precise, and current ontology ancestry places cytosol within cytoplasm. The source evidence is retained; this is a specificity judgment, not a failure of the PAINT placement.

Summary: Dopamine biosynthesis already specifies the supported catecholamine process.

Reason: DDC performs the L-DOPA decarboxylation step rather than merely affecting catecholamine abundance. The PTN000242975 assertion and literal descendant annotations support the broad process, including human target evidence. Existing GO:0042416 dopamine biosynthetic process is a current descendant of this term and provides the informative process annotation. No loss of catecholamine chemistry is implied.

Summary: Retain serotonin biosynthesis as a core performed reaction.

Reason: Human DDC descends from PTN000242975, and the fly, rat and nematode donor records provide experimental grounding for serotonin biosynthesis. This is a phylogenetic placement, not a donor-count vote. DDC directly converts 5-hydroxy-L-tryptophan to serotonin; the curated reaction and the human GO-CAM activity are consistent with this performed catalytic step.

Summary: Retain the historical EC-derived enzyme-class assertion.

Reason: The imported EC-to-GO source maps EC 4.1.1.28 to the true AADC reaction class. Human DDC activity and substrate chemistry independently support it; an EC label alone is not the experimental evidence. The current aggregate annotation uses a different combined-method reference, but that drift does not rewrite this historical source tuple or negate the demonstrated enzyme class.

Summary: Refine amino-acid metabolism to the aromatic amino-acid process performed by DDC.

Reason: DDC catalyzes decarboxylation of the aromatic amino-acid substrates L-DOPA and 5-hydroxy-L-tryptophan. The IPR010977 family assignment is valid, but GO:0009072 aromatic amino acid metabolic process describes this chemistry more precisely than amino acid metabolism. This refines the existing electronic process assertion; the dopamine- and serotonin-producing catalytic steps remain the two physiological cores.

Proposed replacements: aromatic amino acid metabolic process

Summary: Use the already present decarboxylase activities for this broad lyase chemistry.

Reason: The IPR002129 major domain and measured carbon dioxide-releasing reactions support carbon-carbon bond cleavage. GO:0004058 and both substrate-specific activities are current descendants of carbon-carbon lyase activity. The former over-annotation action conflated breadth with biological overreach; the mapping is true but adds no needed specificity.

Summary: Use the existing AADC activities rather than their carboxy-lyase ancestor.

Reason: The historical combined-method source and current family/domain evidence support decarboxylation. The ARBA00026976 branch matching human DDC uses its two FunFam signatures and eukaryotic lineage. Current ontology places AADC and both substrate-specific activities below carboxy-lyase activity. This is true but overly general chemistry, not evidence of an incorrect catalytic role.

Summary: Accept PLP binding as part of DDC catalysis.

Reason: Human DDC binds PLP through a Lys303 internal aldimine. The original human apoenzyme structures and stopped-flow binding experiments in PMID:22143761 support the cofactor-binding activity. The comparison holo structure is pig kidney DDC; it is not a human holo structure. PLP binding supports the two substrate-specific catalytic cores rather than a separate physiological core. The experiments do not establish equivalent activity of the shorter natural products.

Summary: Retain the serotonin-forming substrate-specific activity.

Reason: The curated RHEA:18533 reaction converts 5-hydroxy-L-tryptophan to serotonin and carbon dioxide. The official reaction, conserved pig DDC biochemical annotation and human serotonin GO-CAM activity agree. This supports DDC catalysis, not tryptophan hydroxylation or a claim that every splice product has the same activity.

Summary: Retain the dopamine-forming substrate-specific activity.

Reason: RHEA:12272 specifies L-DOPA decarboxylation to dopamine. In PMID:19703902, human SH-SY5Y lysate supplied with L-DOPA produced dopamine measured by HPLC, and anti-DDC antibody inhibited the DDC assay. The source reaction mapping therefore agrees with target experimental chemistry; DJ-1 regulation is not transferred into DDC's catalytic identity.

Summary: The existing dopamine biosynthetic annotation already specifies this broad amine process.

Reason: Human DDC matches the ARBA00028120 branch using two FunFam signatures and the primate lineage. Its production of dopamine is a genuine biogenic-amine biosynthetic step. Current GO:0042416 ancestry includes GO:0042401, so the existing specific dopamine process makes the broad prediction unnecessary as an additional core assertion. The serotonin branch is retained independently.

Summary: Refine the positive androgen-receptor interaction to nuclear receptor binding.

Reason: PMID:12864730 reports DDC interaction with androgen receptor and ligand-dependent reporter enhancement in prostate cancer cells. Current curated records contain a human AR–human DDC reverse two-hybrid pair and a human LNCaP co-immunoprecipitation pair; the target and human partner sequence/taxon hashes match. Fragment features and a separate rat-AR pull-down are distinguished from full-length human behavior. The original complete paper remained unavailable, so detailed assays are attributed to these curated records and the abstract. AR is an established ligand-regulated nuclear receptor, making GO:0016922 an appropriate binding class. This does not assert a chromatin-bound transcriptional coactivator mechanism or a separate physiological core.

Proposed replacements: nuclear receptor binding

Summary: Retain conserved catalytic participation in dopamine biosynthesis.

Reason: The similarity source P80041 is pig DDC, not a bovine or human accession. Its current experimental L-DOPA-decarboxylase record and the pig enzyme characterization in PMID:8670114 support conserved chemistry; that paper's complete abstract was read, not its full substrate assay tables. Human DDC-dependent dopamine production in PMID:19703902 independently supports the performed step. No human splice-product equivalence is inferred from this transfer.

Summary: Retain the mapped dopamine biosynthetic step.

Reason: The UniPathway mapping represents DDC-catalyzed conversion of L-DOPA to dopamine. The human reaction and target HPLC assay in PMID:19703902 support participation by catalysis, rather than a requirement or substrate-only inference. This agrees with the specific process already supported experimentally and by orthology.

Summary: Retain the experimentally supported DJ-1 interaction as contextual binding.

Reason: The PMID:19703902 Methods and Results describe GST-DJ-1 binding to radiolabeled DDC, anti-DJ-1 co-immunoprecipitation with an IgG control, and stimulation of DDC activity in human dopaminergic cells. A current interaction-query nonmatch does not overturn that primary evidence. DJ-1 has several reported and contested biochemical activities; this review retains a conservative unrefined positive rather than forcing one catalytic partner class. It does not require DDC to activate DJ-1, nor borrow the distinct TH-binding assertion as evidence for the same pair. Supported generic binding remains non-core under the project instruction.

Summary: Retain conserved 5-hydroxy-L-tryptophan decarboxylation.

Reason: The donor P80041 is pig DDC and currently carries an experimental annotation for this reaction. Its native and recombinant enzyme comparison is described in PMID:8670114, although the complete substrate-specific methods were not recovered. The official human reaction and independently curated human assay annotation corroborate transfer of the established enzyme function. Neither the pig experiment nor the human annotation establishes equal activity of all four human products.

Summary: Retain conserved L-DOPA decarboxylation.

Reason: P80041 is the pig DDC ortholog with current experimental L-DOPA-decarboxylase evidence. PMID:8670114 characterizes native pig-kidney and recombinant enzyme, and PMID:19703902 independently measures human DDC-dependent dopamine production. The transfer concerns conserved catalysis, not tissue identity or natural short-product activity.

Summary: Retain directly measured human L-DOPA decarboxylase activity.

Reason: PMID:19703902 assayed human SH-SY5Y cell lysates with L-DOPA and quantified dopamine by HPLC. Anti-DDC antibody inhibited activity relative to IgG, and DJ-1 altered the measured DDC activity. These results support the target catalytic reaction; they do not assign DJ-1's regulatory mechanism or tyrosine hydroxylation to DDC.

Summary: Retain DDC catalysis in dopamine biosynthesis.

Reason: The source's L-DOPA-to-dopamine assay directly measures the step performed by DDC in human dopaminergic cells. The TH/DDC/DJ-1 experiments distinguish the upstream tyrosine hydroxylase reaction from DDC decarboxylation. DDC participates by catalysis, rather than merely through association with dopamine-production machinery.

Summary: Retain the curated serotonin-producing activity with explicit source-access limits.

Reason: The accessible PMID:16338639 abstract describes human AADC expression and activity assays in dopamine-synthesis experiments. The complete assay paper remained inaccessible, so a 5-hydroxytryptophan assay in that paper was not independently verified. Human DDC serotonin-producing activity is independently supported by its curated reaction and the wider biochemical literature. Retain the experimental annotation by curator deference; do not present the generic abstract sentence as direct verification of that substrate-specific assay.

Summary: Retain binding to the catalytic partner tyrosine hydroxylase.

Reason: The PMID:19703902 Results describe binding of radiolabeled DDC to GST-TH rather than GST and recovery of a TH/DDC/DJ-1 complex. Thus the source contains direct pair evidence in addition to ternary co-immunoprecipitation. TH is a catalytic protein, satisfying enzyme binding. This contextual pathway interaction does not establish substrate channeling, a separate scaffold activity, or DDC-mediated activation of TH. The supplementary assay is described in the main Results; its separate figure pixels were not inspected.

Summary: Retain source-specific urinary extracellular-vesicle detection.

Reason: The source-linked NHLBI urinary-exosome protein table lists DDC, RefSeq NP_000781, with 11 peptides under study reference 2. The original Methods describe pooled human urine and differential centrifugation followed by LC-MS/MS. This is positive target detection in the isolated fraction, not proof of extracellular catalytic function, vesicle biogenesis, or localization of every splice product. The protein-table entry alone does not establish peptide uniqueness between DDC products. Retain the contextual cellular-component observation.

Summary: Retain the cytosolic serotonin reaction location.

Reason: The Reactome serotonin reaction resolves through its catalyst to the PLP-containing human DDC homodimer, with DDC coordinates 1–480 and cytosol compartment. This is the reference enzyme model, not evidence that the shorter products are present in the same catalytic assembly. It supports the core cytosolic reaction and provides a more precise location than cytoplasm.

Summary: Retain the cytosolic dopamine reaction location.

Reason: The Reactome L-DOPA-to-dopamine reaction resolves to the same PLP-containing human DDC homodimer in cytosol, with the reference 1–480 sequence. The source and product coordinates were checked independently of the serotonin reaction. It supports the physiological catalytic location without excluding contextual extracellular-vesicle detection.

Summary: Accept the human AADC activity annotation.

Reason: PMID:16338639 explicitly describes assays of expressed human AADC in dopamine-synthesis experiments. This supports the enzyme class; the complete methods, assay conditions and any additional substrates were not accessible. The broad annotation remains valid, while the core summary uses the two established substrate-specific reactions.

Summary: Accept the author-stated AADC activity, distinguishing background chemistry from experimental species.

Reason: PMID:7567987 states the L-DOPA-to-dopamine and 5-hydroxytryptophan-to-serotonin reactions. Its expression-library experiment is from rat insulinoma cells, not a human purified-enzyme assay. This source supports the TAS statement of conserved enzyme function; it does not by itself establish human product-specific kinetics or activity of the four human splice products. Only the complete abstract was available in this assessment.