id: P42765
gene_symbol: ACAA2
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: >-
  ACAA2 (3-ketoacyl-CoA thiolase, mitochondrial; also called acetyl-CoA
  acyltransferase 2 or T1; EC 2.3.1.16) is a soluble enzyme of the mitochondrial
  matrix that catalyzes the fourth and final step of each cycle of the fatty acid
  beta-oxidation spiral. Using free coenzyme A, it performs the thiolytic cleavage
  of a 3-ketoacyl-CoA (3-oxoacyl-CoA) into acetyl-CoA and a fatty acyl-CoA shortened
  by two carbon atoms, preferring medium- to long-chain unbranched (straight-chain)
  substrates. The enzyme assembles as a homotetramer and belongs to the thiolase
  family of the thiolase-like superfamily, using an active-site cysteine (Cys92) to
  form an acyl-enzyme thioester intermediate and a second cysteine (Cys382) as the
  catalytic proton donor/acceptor. In the reverse direction it can condense two
  acetyl-CoA molecules into acetoacetyl-CoA (EC 2.3.1.9), and it also displays a slow
  intrinsic acyl-CoA thioesterase (hydrolase) side activity on various fatty
  acyl-CoAs. ACAA2 is a distinct gene product from HADHB (the long-chain thiolase of
  the membrane-bound mitochondrial trifunctional protein) and from ACAT1 (the
  mitochondrial acetoacetyl-CoA/ketone-body thiolase). It has additionally been
  reported to bind the pro-apoptotic protein BNIP3 and attenuate BNIP3-driven
  apoptosis, providing a possible link between mitochondrial fatty acid metabolism
  and apoptotic signaling.
existing_annotations:
- term:
    id: GO:0003985
    label: acetyl-CoA C-acetyltransferase activity
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: enables
  review:
    summary: >-
      Phylogenetic (IBA) propagation of acetyl-CoA C-acetyltransferase activity
      (EC 2.3.1.9), the acetoacetyl-CoA-forming/cleaving reaction. ACAA2 does
      possess this activity (demonstrated biochemically and structurally), but it is
      a secondary/biosynthetic capability; the core physiological role is the
      C-acyltransferase (thiolase) reaction on longer-chain 3-oxoacyl-CoAs. Keep,
      but mark as non-core.
    action: KEEP_AS_NON_CORE
    reason: >-
      Supported by direct evidence (PMID:25478839) showing significant biosynthetic
      thiolase (acetoacetyl-CoA) activity, but the chain-shortening beta-oxidation
      thiolase reaction (GO:0003988) is the core function.
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: is_active_in
  review:
    summary: >-
      Phylogenetic propagation of mitochondrial localization. Correct and consistent
      with experimental localization (PMID:18371312, HPA, mitochondrial proteome
      studies). A more precise term (mitochondrial matrix, GO:0005759) is also
      annotated; this broader term is acceptable.
    action: KEEP_AS_NON_CORE
- term:
    id: GO:0006635
    label: fatty acid beta-oxidation
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: >-
      Phylogenetic propagation of the core biological process. ACAA2 catalyzes the
      final (thiolytic) step of each beta-oxidation cycle. Strongly supported and
      represents a core process for the gene.
    action: ACCEPT
- term:
    id: GO:0003985
    label: acetyl-CoA C-acetyltransferase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: enables
  review:
    summary: >-
      Electronic (ARBA/Rhea/EC) assertion of acetyl-CoA C-acetyltransferase activity
      (EC 2.3.1.9), the same biosynthetic acetoacetyl-CoA reaction captured by the
      IBA and IDA annotations. Redundant with the experimentally supported
      annotation; keep as non-core.
    action: KEEP_AS_NON_CORE
- term:
    id: GO:0003986
    label: acetyl-CoA hydrolase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: enables
  review:
    summary: >-
      Electronic (EC 3.1.2.1) assertion of acetyl-CoA hydrolase activity, an in-vitro
      thioesterase side reaction. PMID:25478839 confirmed low intrinsic acyl-CoA
      thioesterase activity (kcat ~0.02/s for octanoyl-CoA), so the activity is real
      but physiologically minor. Keep as non-core; the principal hydrolase substrate
      observed was butyryl-CoA, not acetyl-CoA specifically.
    action: KEEP_AS_NON_CORE
- term:
    id: GO:0003988
    label: acetyl-CoA C-acyltransferase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: enables
  review:
    summary: >-
      Electronic (EC 2.3.1.16 / Rhea) assertion of acetyl-CoA C-acyltransferase
      activity. This is the core 3-ketoacyl-CoA thiolase molecular function of ACAA2
      and is independently supported by direct assay (PMID:25478839). Accept.
    action: ACCEPT
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  review:
    summary: >-
      Electronic localization from the UniProt subcellular-location vocabulary.
      Correct; ACAA2 is a mitochondrial (matrix) protein. Non-core (matrix, GO:0005759, is the specific core location).
    action: KEEP_AS_NON_CORE
- term:
    id: GO:0016746
    label: acyltransferase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  review:
    summary: >-
      InterPro2GO mapping to the high-level parent term acyltransferase activity.
      Correct in direction but far less informative than the specific thiolase MF
      (GO:0003988) that is already annotated with experimental evidence. Over-general.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Redundant generic ancestor of the experimentally supported GO:0003988; carries
      no information beyond the specific thiolase activity term.
- term:
    id: GO:0016747
    label: acyltransferase activity, transferring groups other than amino-acyl groups
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  review:
    summary: >-
      InterPro2GO mapping to an intermediate (still generic) acyltransferase parent.
      As with GO:0016746, this is a non-informative ancestor of the specific thiolase
      activity GO:0003988 already annotated with direct evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Over-general ancestor of GO:0003988; the specific thiolase MF term should be
      used.
- term:
    id: GO:0052815
    label: medium-chain fatty acyl-CoA hydrolase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000116
  qualifier: enables
  review:
    summary: >-
      Rhea-mapped assertion of medium-chain (C6-C12) acyl-CoA hydrolase activity,
      derived from the in-vitro thioesterase side reactions of T1. PMID:25478839
      confirmed low acyl-CoA thioesterase activity across chain lengths (kcat
      ~0.02/s). The activity is real but a minor side reaction, not the core
      function. Keep as non-core.
    action: KEEP_AS_NON_CORE
- term:
    id: GO:0052816
    label: long-chain fatty acyl-CoA hydrolase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000116
  qualifier: enables
  review:
    summary: >-
      Rhea-mapped long-chain acyl-CoA hydrolase (thioesterase) activity from the same
      low-level in-vitro side reactions. Physiologically minor relative to the
      thiolase function. Keep as non-core.
    action: KEEP_AS_NON_CORE
- term:
    id: GO:0141126
    label: short-chain fatty acyl-CoA hydrolase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000116
  qualifier: enables
  review:
    summary: >-
      Rhea-mapped short-chain acyl-CoA hydrolase activity. PMID:25478839 noted the
      fastest hydrolysis rate was for butyryl-CoA (a short-chain substrate), so this
      is the best-supported of the hydrolase terms, but it remains a slow side
      reaction. Keep as non-core.
    action: KEEP_AS_NON_CORE
- term:
    id: GO:0006635
    label: fatty acid beta-oxidation
  evidence_type: IEA
  original_reference_id: GO_REF:0000041
  qualifier: involved_in
  review:
    summary: >-
      UniPathway-based electronic assertion of involvement in fatty acid
      beta-oxidation, the core process. Consistent with the IBA annotation and with
      UniProt PATHWAY ("Lipid metabolism; fatty acid beta-oxidation"). Accept.
    action: ACCEPT
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: IDA
  original_reference_id: GO_REF:0000052
  qualifier: located_in
  review:
    summary: >-
      Direct immunofluorescence (Human Protein Atlas) localization to mitochondrion.
      Correct and consistent with all other localization evidence. Non-core (matrix, GO:0005759, is the specific core location).
    action: KEEP_AS_NON_CORE
- term:
    id: GO:0003986
    label: acetyl-CoA hydrolase activity
  evidence_type: EXP
  original_reference_id: PMID:25478839
  qualifier: enables
  review:
    summary: >-
      Experimental annotation from the crystallographic/biochemical study, which
      demonstrated intrinsic acyl-CoA thioesterase (hydrolase) activity of human T1.
      The activity is genuine but very slow (kcat ~0.02/s) and is described as a
      possible side reaction producing acetate, not the core role. Keep as non-core.
    action: KEEP_AS_NON_CORE
    reason: >-
      Direct evidence supports the activity, but it is a minor in-vitro side reaction
      relative to the thiolase function.
    supported_by:
    - reference_id: PMID:25478839
      supporting_text: >-
        Solution studies confirm that hT1 has low acyl-CoA thioesterase activity for
        fatty acyl-CoA substrates.
      full_text_unavailable: true
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: HTP
  original_reference_id: PMID:34800366
  qualifier: located_in
  review:
    summary: >-
      High-throughput localization from a high-confidence human mitochondrial
      proteome study. Corroborates the well-established mitochondrial localization.
      Non-core (matrix, GO:0005759, is the specific core location).
    action: KEEP_AS_NON_CORE
- term:
    id: GO:0003985
    label: acetyl-CoA C-acetyltransferase activity
  evidence_type: IDA
  original_reference_id: PMID:25478839
  qualifier: enables
  review:
    summary: >-
      Direct-assay evidence that T1 has significant biosynthetic (acetoacetyl-CoA
      synthesizing/cleaving) thiolase activity, i.e. acetyl-CoA C-acetyltransferase
      (EC 2.3.1.9). The activity is real and well measured (KM 9.2 uM for
      acetoacetyl-CoA), but it is a secondary capability; the chain-shortening
      thiolase reaction (GO:0003988) is the core function. Keep as non-core.
    action: KEEP_AS_NON_CORE
    reason: >-
      Experimentally demonstrated, but secondary to the core C-acyltransferase
      thiolase activity in beta-oxidation.
    supported_by:
    - reference_id: PMID:25478839
      supporting_text: >-
        It is also shown that T1 has significant biosynthetic thiolase activity,
        which is predicted to be of physiological importance.
      full_text_unavailable: true
- term:
    id: GO:0003988
    label: acetyl-CoA C-acyltransferase activity
  evidence_type: IDA
  original_reference_id: PMID:25478839
  qualifier: enables
  review:
    summary: >-
      Direct-assay annotation of the core 3-ketoacyl-CoA thiolase activity
      (EC 2.3.1.16) confirmed by the structural/biochemical characterization of human
      T1 as a degradative tetrameric thiolase. This is THE core molecular function of
      ACAA2 in beta-oxidation. Accept.
    action: ACCEPT
    reason: >-
      Core molecular function; supported by direct enzymatic and structural data.
    supported_by:
    - reference_id: PMID:25478839
      supporting_text: >-
        The structures confirm the tetrameric quaternary structure of this
        degradative thiolase.
      full_text_unavailable: true
- term:
    id: GO:0047617
    label: fatty acyl-CoA hydrolase activity
  evidence_type: IMP
  original_reference_id: PMID:25478839
  qualifier: enables
  review:
    summary: >-
      Annotation of fatty acyl-CoA hydrolase (thioesterase) activity, based on the
      observed intrinsic hydrolysis of fatty acyl-CoAs (and supported by mutagenesis
      of the catalytic Cys92/Cys382 that reduced hydrolase activity). A genuine but
      slow side reaction; keep as non-core.
    action: KEEP_AS_NON_CORE
    reason: >-
      Direct evidence supports a real but minor in-vitro thioesterase side activity.
    supported_by:
    - reference_id: PMID:25478839
      supporting_text: >-
        owing to the intrinsic acyl-CoA thioesterase activity of hT1
      full_text_unavailable: true
- term:
    id: GO:0005759
    label: mitochondrial matrix
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-8874745
  qualifier: located_in
  review:
    summary: >-
      Reactome-asserted localization to the mitochondrial matrix. This is the most
      precise and correct localization for ACAA2, a soluble matrix thiolase (distinct
      from the inner-membrane MTP thiolase HADHB). Accept as core localization.
    action: ACCEPT
- term:
    id: GO:0071456
    label: cellular response to hypoxia
  evidence_type: IDA
  original_reference_id: PMID:18371312
  qualifier: involved_in
  review:
    summary: >-
      Based on the BNIP3 study, where ACAA2 abolished apoptosis induced by
      hypoxia-driven BNIP3 overexpression. The connection to hypoxia is indirect
      (via BNIP3, a hypoxia-induced pro-apoptotic factor) and rests on a single
      overexpression study. Keep but mark as non-core/contextual.
    action: KEEP_AS_NON_CORE
    reason: >-
      Indirect, single-study (overexpression) evidence; not a core function of the
      thiolase.
    supported_by:
    - reference_id: PMID:18371312
      supporting_text: >-
        the apoptosis induced by over-expressed BNIP3 via transfection or hypoxia
        treatment was abolished by ACAA2
      full_text_unavailable: true
- term:
    id: GO:1902109
    label: negative regulation of mitochondrial membrane permeability involved in
      apoptotic process
  evidence_type: IDA
  original_reference_id: PMID:18371312
  qualifier: involved_in
  review:
    summary: >-
      Based on ACAA2 abolishing BNIP3-induced apoptosis and mitochondrial damage in
      HepG2 and U-2 OS cells. A plausible secondary (moonlighting) role linking fatty
      acid metabolism to apoptosis, but from a single overexpression study. Keep as
      non-core.
    action: KEEP_AS_NON_CORE
    reason: >-
      Real but single-study, overexpression-based; not the core catalytic function.
    supported_by:
    - reference_id: PMID:18371312
      supporting_text: >-
        the apoptosis induced by over-expressed BNIP3 via transfection or hypoxia
        treatment was abolished by ACAA2
      full_text_unavailable: true
- term:
    id: GO:0003723
    label: RNA binding
  evidence_type: HDA
  original_reference_id: PMID:22658674
  qualifier: enables
  review:
    summary: >-
      Detected in a proteome-wide mRNA-interactome capture screen in HeLa cells that
      identified many metabolic enzymes as RNA-binding. There is no gene-specific
      functional validation of RNA binding for ACAA2 and no proposed mechanism; this
      is a high-throughput moonlighting candidate, not a characterized function.
      Keep as non-core.
    action: KEEP_AS_NON_CORE
    reason: >-
      Orthogonal high-throughput detection only; no functional follow-up specific to
      ACAA2.
    supported_by:
    - reference_id: PMID:22658674
      supporting_text: >-
        shedding light on RBPs in disease, RNA-binding enzymes of intermediary
        metabolism
      full_text_unavailable: true
- term:
    id: GO:1901029
    label: negative regulation of mitochondrial outer membrane permeabilization involved
      in apoptotic signaling pathway
  evidence_type: IDA
  original_reference_id: PMID:18371312
  qualifier: involved_in
  review:
    summary: >-
      Same BNIP3 evidence as the related membrane-permeability term. ACAA2
      counteracts BNIP3-driven mitochondrial outer-membrane permeabilization and
      apoptosis. A secondary contextual role from a single overexpression study;
      keep as non-core.
    action: KEEP_AS_NON_CORE
    reason: >-
      Single overexpression study; secondary to the core thiolase function.
    supported_by:
    - reference_id: PMID:18371312
      supporting_text: >-
        ACAA2 was also found to co-localize with BNIP3 in mitochondria.
      full_text_unavailable: true
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:18371312
  qualifier: enables
  review:
    summary: >-
      IPI annotation recording the physical interaction with BNIP3 (UniProtKB:Q12983),
      confirmed by yeast two-hybrid, pull-down and co-immunoprecipitation. The
      interaction is real and well supported, but "protein binding" is an
      uninformative molecular-function term and is not a core function. Keep as
      non-core (the biological consequence is captured by the apoptosis-regulation
      process terms).
    action: KEEP_AS_NON_CORE
    reason: >-
      Documents a verified BNIP3 interaction, but the bare protein-binding MF term is
      uninformative and should not be treated as a core function.
    supported_by:
    - reference_id: PMID:18371312
      supporting_text: >-
        The interaction between BNIP3 and ACAA2 was confirmed by pull-down and
        co-immunoprecipitation assays.
      full_text_unavailable: true
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: IDA
  original_reference_id: PMID:18371312
  qualifier: located_in
  review:
    summary: >-
      Direct localization to mitochondria from the BNIP3 study (co-localization
      imaging). Consistent with all other localization evidence. Non-core (matrix, GO:0005759, is the specific core location).
    action: KEEP_AS_NON_CORE
    supported_by:
    - reference_id: PMID:18371312
      supporting_text: >-
        ACAA2 was also found to co-localize with BNIP3 in mitochondria.
      full_text_unavailable: true
- term:
    id: GO:0003988
    label: acetyl-CoA C-acyltransferase activity
  evidence_type: NAS
  original_reference_id: PMID:8241273
  qualifier: enables
  review:
    summary: >-
      Author-statement (NAS) assignment of the thiolase activity from the original
      cDNA cloning paper, which identified the gene as human mitochondrial
      3-oxoacyl-CoA thiolase. The activity assignment is correct (matches the core
      MF) though the cited paper is sequence/expression-based rather than an enzyme
      assay. Accept; corroborated by the later direct-assay annotation.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:8241273
      supporting_text: >-
        The cDNA sequence of human mitochondrial 3-oxoacyl-CoA thiolase was determined
      full_text_unavailable: true
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: NAS
  original_reference_id: PMID:8241273
  qualifier: located_in
  review:
    summary: >-
      Author-statement mitochondrial localization from the cloning paper (the protein
      is named "human mitochondrial 3-oxoacyl-CoA thiolase" and carries a
      mitochondrial transit sequence). Correct. Non-core (matrix, GO:0005759, is the specific core location).
    action: KEEP_AS_NON_CORE
- term:
    id: GO:0006695
    label: cholesterol biosynthetic process
  evidence_type: NAS
  original_reference_id: PMID:8241273
  qualifier: involved_in
  review:
    summary: >-
      NAS annotation linking ACAA2 to cholesterol biosynthesis. The cited cloning
      paper (PMID:8241273) describes only cDNA sequencing, rat homology, and Northern
      expression; its abstract makes no claim about cholesterol biosynthesis. The
      assertion is also biologically implausible: ACAA2 is a mitochondrial-matrix
      beta-oxidation (catabolic) thiolase, whereas cholesterol synthesis proceeds via
      the cytosolic acetoacetyl-CoA thiolase/HMG-CoA pathway. This is most likely a
      confusion with the cytosolic/peroxisomal thiolases. Remove.
    action: REMOVE
    reason: >-
      Unsupported by the cited reference and contradicted by the established
      catabolic, mitochondrial role of ACAA2; cholesterol biosynthesis uses cytosolic
      thiolase/HMG-CoA enzymes, not mitochondrial ACAA2.
core_functions:
- description: >-
    Catalyzes the final thiolytic (CoA-dependent) cleavage step of each cycle of
    mitochondrial fatty acid beta-oxidation, converting a 3-ketoacyl-CoA into
    acetyl-CoA and a fatty acyl-CoA shortened by two carbons, with a preference for
    medium- to long-chain unbranched substrates. Acts as a homotetramer in the
    mitochondrial matrix.
  supported_by:
  - reference_id: PMID:25478839
    supporting_text: >-
      The structures confirm the tetrameric quaternary structure of this degradative
      thiolase.
    full_text_unavailable: true
  - reference_id: PMID:8241273
    supporting_text: >-
      The cDNA sequence of human mitochondrial 3-oxoacyl-CoA thiolase was determined
    full_text_unavailable: true
  molecular_function:
    id: GO:0003988
    label: acetyl-CoA C-acyltransferase activity
  directly_involved_in:
  - id: GO:0006635
    label: fatty acid beta-oxidation
  locations:
  - id: GO:0005759
    label: mitochondrial matrix
proposed_new_terms: []
suggested_questions:
- question: >-
    Is ACAA2's biosynthetic acetoacetyl-CoA-forming (acetyl-CoA C-acetyltransferase)
    activity physiologically relevant in vivo, or is it primarily a reflection of the
    reversibility of the thiolase reaction measured in vitro?
- question: >-
    Is the anti-apoptotic, BNIP3-attenuating role of ACAA2 a genuine endogenous
    function or an artifact of overexpression, and does it depend on the catalytic
    activity of the enzyme?
- question: >-
    Does ACAA2 have any bona fide RNA-binding function, or is its appearance in
    mRNA-interactome capture a non-functional consequence of CoA/nucleotide-binding
    surfaces?
suggested_experiments:
- description: >-
    Determine the chain-length substrate specificity of recombinant human ACAA2 with
    a panel of straight-chain 3-ketoacyl-CoA substrates (C4-C16) to define its
    physiological substrate range relative to HADHB and ACAT1.
- description: >-
    Use ACAA2 knockout/knockdown in human hepatocytes followed by acylcarnitine and
    organic-acid profiling to test the in-vivo contribution of ACAA2 to
    beta-oxidation flux and the proposed acetate side-production.
- description: >-
    Test whether catalytically dead ACAA2 (C92A/C382A) still attenuates BNIP3-induced
    apoptosis, to determine whether the apoptosis-modulating role is independent of
    thiolase catalysis.
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:0000041
  title: Gene Ontology annotation based on UniPathway vocabulary mapping
  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:0000052
  title: Gene Ontology annotation based on curation of immunofluorescence data
  findings: []
- id: GO_REF:0000116
  title: Automatic Gene Ontology annotation based on Rhea mapping
  findings: []
- id: GO_REF:0000120
  title: Combined Automated Annotation using Multiple IEA Methods
  findings: []
- id: PMID:18371312
  title: Acetyl-Coenzyme A acyltransferase 2 attenuates the apoptotic effects of BNIP3
    in two human cell lines.
  findings:
  - statement: >-
      Identifies ACAA2 as a BNIP3 binding partner (membrane yeast two-hybrid,
      pull-down, co-IP) that co-localizes with BNIP3 in mitochondria and abolishes
      BNIP3/hypoxia-induced apoptosis in HepG2 and U-2 OS cells, linking fatty acid
      metabolism to apoptosis.
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: >-
      Abstract verified; supports the BNIP3 interaction (GO:0005515) and the
      apoptosis/hypoxia process annotations. Single-lab overexpression study, so the
      apoptosis-regulation role is contextual/non-core.
- id: PMID:22658674
  title: Insights into RNA biology from an atlas of mammalian mRNA-binding proteins.
  findings:
  - statement: >-
      Proteome-wide mRNA-interactome capture in HeLa cells identifying 860 RBPs
      including many intermediary-metabolism enzymes; basis for the HDA RNA-binding
      annotation, with no ACAA2-specific functional validation.
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: >-
      Abstract verified; a high-throughput screen only. Supports the RNA-binding
      annotation as a moonlighting candidate, not a characterized ACAA2 function.
- id: PMID:25478839
  title: 'The crystal structure of human mitochondrial 3-ketoacyl-CoA thiolase (T1):
    insight into the reaction mechanism of its thiolase and thioesterase activities.'
  findings:
  - statement: >-
      Crystal structures (apo and CoA-bound, 2.0 A) confirm ACAA2/T1 is a tetrameric
      degradative thiolase; demonstrates significant biosynthetic (acetoacetyl-CoA)
      thiolase activity and low intrinsic acyl-CoA thioesterase (hydrolase) activity,
      fastest for butyryl-CoA. Provides the EXP/IDA basis for the thiolase and
      hydrolase molecular-function annotations.
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      Abstract verified against UniProt (PDB 4C2J/4C2K, Cys92/Cys382 active site,
      kinetics). Primary structural/biochemical reference establishing ACAA2's core
      and side activities.
- id: PMID:34800366
  title: Quantitative high-confidence human mitochondrial proteome and its dynamics
    in cellular context.
  findings:
  - statement: >-
      High-confidence human mitochondrial proteome study supporting mitochondrial
      localization of ACAA2 (HTP evidence).
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: >-
      Supports mitochondrial localization; corroborative high-throughput evidence
      only.
- id: PMID:8241273
  title: Cloning and sequence analysis of a full length cDNA encoding human mitochondrial
    3-oxoacyl-CoA thiolase.
  findings:
  - statement: >-
      Original cDNA cloning of human mitochondrial 3-oxoacyl-CoA thiolase (397 aa,
      86.6% identity to rat), expressed in liver, fibroblasts and muscle. Establishes
      gene identity and mitochondrial assignment; makes no claim about cholesterol
      biosynthesis.
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: >-
      Abstract verified. Supports gene identity and mitochondrial thiolase
      assignment; does NOT support the NAS cholesterol-biosynthesis annotation, which
      is recommended for removal.
- id: Reactome:R-HSA-8874745
  title: ACAA2 tetramer transfers acyl group from Ac-CoA to acyl-CoA forming 3OA-CoA
    and CoA-SH
  findings: []