PFKM

UniProt ID: P08237
Organism: Homo sapiens
Review Status: INITIALIZED
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Gene Description

PFKM is the muscle isozyme of 6-phosphofructokinase (phosphofructokinase-1, PFK-1; EC 2.7.1.11), the enzyme that catalyzes the committed, rate-limiting step of glycolysis - the ATP-dependent phosphorylation of D-fructose 6-phosphate to fructose 1,6-bisphosphate, requiring Mg2+. It is a major allosteric control point of the pathway, activated by AMP, ADP and fructose 2,6-bisphosphate and inhibited by ATP and citrate. The active enzyme is a tetramer assembled from three subunit types - PFKM (muscle), PFKL (liver) and PFKP (platelet); skeletal muscle contains essentially the M4 homotetramer, whereas erythrocytes contain a mixture of M/L hybrids. Each subunit is a two-domain protein with an N-terminal catalytic domain and a C-terminal regulatory domain that binds allosteric effectors. PFKM acts in the cytosol. Loss-of-function variants in PFKM cause glycogen storage disease type VII (Tarui disease), characterized by exercise intolerance, muscle cramps, exertional myopathy and compensated hemolysis, reflecting the block of muscle glycolysis and its knock-on effects on glycogenolysis and erythrocyte metabolism.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0003872 6-phosphofructokinase activity
IBA
GO_REF:0000033 		ACCEPT
Summary: Core molecular function - PFKM is a 6-phosphofructokinase that phosphorylates fructose 6-phosphate to fructose 1,6-bisphosphate. Phylogenetically inferred across the PFKA family and directly supported by experimental data on the human muscle enzyme.
Reason: This is the defining molecular function of PFKM, well supported across all evidence codes and by the UniProt catalytic activity annotation (EC 2.7.1.11). The IBA is at the correct level of specificity.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
Catalyzes the phosphorylation of D-fructose 6-phosphate to fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis.
GO:0006002 fructose 6-phosphate metabolic process
IBA
GO_REF:0000033 		ACCEPT
Summary: Fructose 6-phosphate is the substrate of PFKM, so participation in F6P metabolism is a direct consequence of the catalytic activity.
Reason: Consistent with the reaction catalyzed; F6P is consumed by PFKM in the committed step of glycolysis.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
Catalyzes the phosphorylation of D-fructose 6-phosphate to fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis.
GO:0030388 fructose 1,6-bisphosphate metabolic process
IBA
GO_REF:0000033 		ACCEPT
Summary: Fructose 1,6-bisphosphate is the product of the PFKM-catalyzed reaction, so PFKM participates in its metabolism (production).
Reason: Directly reflects the product of the catalytic reaction.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
Catalyzes the phosphorylation of D-fructose 6-phosphate to fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis.
GO:0061621 canonical glycolysis
IBA
GO_REF:0000033 		ACCEPT
Summary: PFKM catalyzes the committed step of glycolysis and is a canonical component of the pathway.
Reason: Central role in glycolysis, phylogenetically conserved and experimentally established. Appropriate biological process term.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-
PMID:24817713
The main regulator of glycolysis, 6-phosphofructokinase (EC 2.7.1.11; Pfk), catalyzes the Mg-ATP-dependent formation of fructose 1,6-bisphosphate from fructose 6-phosphate
GO:0005945 6-phosphofructokinase complex
IBA
GO_REF:0000033 		ACCEPT
Summary: The active PFK enzyme is a tetramer; in muscle it is the M4 homotetramer. PFKM is a subunit of the 6-phosphofructokinase complex.
Reason: Well supported - the enzyme functions as a tetramer composed of PFKM, PFKL and PFKP subunits, and PFKM is part of this complex.
Supporting Evidence:
PMID:6444721
These data demonstrate that muscle and liver PFKs are distinct homotetramers-i.e., M(4) and L(4), respectively
file:human/PFKM/PFKM-uniprot.txt
Phosphofructokinase (PFK) enzyme functions as a tetramer composed of different combinations
GO:0016020 membrane
IBA
GO_REF:0000033 		MARK AS OVER ANNOTATED
Summary: An IBA "is_active_in membrane" annotation. PFKM is a soluble cytosolic enzyme; membrane association is at best transient/regulatory (e.g. actin, caveolin, V-ATPase in specific cell types), not the site of its core catalytic activity.
Reason: The generic "membrane" location does not represent the core cytosolic localization of this glycolytic enzyme. Any membrane association is peripheral and cell-type-specific rather than a defining compartment. The cytosol annotations capture the primary localization.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm
GO:0070095 fructose-6-phosphate binding
IBA
GO_REF:0000033 		ACCEPT
Summary: PFKM binds fructose 6-phosphate as its phosphoacceptor substrate. Substrate binding is intrinsic to the enzyme mechanism.
Reason: Directly supported - F6P is the substrate and specific F6P/substrate binding residues are annotated in the structure. Kinetic F-6-P affinity has been measured for the M-type isozyme.
Supporting Evidence:
PMID:8780720
lower affinity for F-6-P showed by the M-type isozyme
GO:0003872 6-phosphofructokinase activity
IEA
GO_REF:0000120 		ACCEPT
Summary: Electronic assertion of the core 6-phosphofructokinase activity via UniRule/InterPro and the RHEA:16109 / EC 2.7.1.11 mapping.
Reason: Correct core molecular function, consistent with the experimental and IBA annotations of the same term.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
EC=2.7.1.11
GO:0005524 ATP binding
IEA
GO_REF:0000002 		ACCEPT
Summary: PFKM uses ATP as the phosphoryl donor and has defined ATP-binding residues; ATP binding is intrinsic to the kinase reaction.
Reason: Well supported - ATP is a co-substrate; UniProt annotates multiple ATP-binding sites and ATP additionally acts as an allosteric inhibitor. Confirmed experimentally.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
/ligand="ATP"
GO:0005737 cytoplasm
IEA
GO_REF:0000120 		ACCEPT
Summary: PFKM is a cytoplasmic/cytosolic enzyme. Consistent with the UniProt subcellular location and the cytosol annotations.
Reason: Correct localization, though the more specific "cytosol" term is preferable and is also annotated. Accepting the broader parent as-is.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm
GO:0006002 fructose 6-phosphate metabolic process
IEA
GO_REF:0000002 		ACCEPT
Summary: Electronic (InterPro) inference of F6P metabolism, consistent with the enzyme substrate.
Reason: Correct - F6P is the substrate consumed by PFKM. Duplicates the IBA and experimental annotations of the same term.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
Catalyzes the phosphorylation of D-fructose 6-phosphate to fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis.
GO:0006096 glycolytic process
IEA
GO_REF:0000120 		ACCEPT
Summary: Electronic inference (UniRule/InterPro/UniPathway) that PFKM participates in glycolysis. This is the core biological process.
Reason: PFKM catalyzes the committed step of glycolysis; the annotation is correct and at an appropriate level.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-
GO:0005515 protein binding
IPI
PMID:21988832
Toward an understanding of the protein interaction network o... 		MARK AS OVER ANNOTATED
Summary: High-throughput protein interaction annotation from a proteome-scale human liver interactome map. "Protein binding" is uninformative about molecular function.
Reason: The bare "protein binding" term conveys no specific functional information and derives from a large-scale interactome screen. Per curation policy such IPIs are marked as over-annotated rather than removed; the informative functions (kinase activity, complex assembly) are captured elsewhere.
Supporting Evidence:
PMID:21988832
Proteome-scale protein interaction maps are available for many organisms
GO:0005515 protein binding
IPI
PMID:25416956
A proteome-scale map of the human interactome network. 		MARK AS OVER ANNOTATED
Summary: High-throughput binary interaction from a proteome-scale human interactome (HuRI) map. Uninformative "protein binding".
Reason: Bare "protein binding" from a systematic interactome screen adds no specific functional detail; retained but flagged as over-annotated per policy.
Supporting Evidence:
PMID:25416956
Here, we describe a systematic map of
GO:0005515 protein binding
IPI
PMID:28514442
Architecture of the human interactome defines protein commun... 		MARK AS OVER ANNOTATED
Summary: High-throughput interaction from BioPlex 2.0 affinity-purification mass spectrometry. Uninformative "protein binding".
Reason: Bare "protein binding" from a large-scale AP-MS interactome dataset; no specific molecular function conveyed. Flagged as over-annotated per policy.
Supporting Evidence:
PMID:28514442
we present BioPlex 2.0
GO:0005515 protein binding
IPI
PMID:33961781
Dual proteome-scale networks reveal cell-specific remodeling... 		MARK AS OVER ANNOTATED
Summary: High-throughput interaction from BioPlex 3.0 affinity-purification networks. Uninformative "protein binding".
Reason: Bare "protein binding" from a proteome-scale AP-MS interactome; no specific function conveyed. Flagged as over-annotated per policy.
Supporting Evidence:
PMID:33961781
Through affinity-purification
GO:0005515 protein binding
IPI
PMID:36115835
Quantitative fragmentomics allow affinity mapping of interac... 		MARK AS OVER ANNOTATED
Summary: Interactions mapped by quantitative fragmentomics/affinity mapping (many PDZ-domain partners). Uninformative "protein binding".
Reason: Bare "protein binding" from a high-throughput affinity-mapping study; the many PDZ partners are unlikely to reflect the core muscle glycolytic function. Flagged as over-annotated per policy.
Supporting Evidence:
PMID:36115835
Quantitative fragmentomics allow affinity mapping of interactomes.
GO:0005515 protein binding
IPI
PMID:6444721
Isozymes of human phosphofructokinase: identification and su... 		MARK AS OVER ANNOTATED
Summary: IPI to PFKL (P17858) from the isozyme hybridization study. The specific biology (M/L subunit tetramerization) is better captured by the complex and identical/kinase binding annotations. Bare "protein binding" is uninformative.
Reason: While the underlying interaction (PFKM-PFKL) is real and biologically meaningful for hybrid tetramer formation, the generic "protein binding" term is uninformative; the same paper supports the more specific 6-phosphofructokinase complex and kinase binding annotations. Flagged as over-annotated per policy.
Supporting Evidence:
PMID:6444721
These multimolecular forms result from the random polymerization of two distinct subunits, M (muscle type) and L (liver type)
GO:0042802 identical protein binding
IPI
PMID:25416956
A proteome-scale map of the human interactome network. 		KEEP AS NON CORE
Summary: PFKM self-association (M4 homotetramer). Identical protein binding reflects the homotetrameric assembly of the muscle enzyme.
Reason: The muscle enzyme is an M4 homotetramer, so PFKM binds identical subunits. This is a real, informative property, but it is a structural corollary of complex assembly rather than the primary catalytic function; kept as non-core.
Supporting Evidence:
PMID:6444721
muscle and liver PFKs are distinct homotetramers-i.e., M(4) and L(4)
GO:0042802 identical protein binding
IPI
PMID:6444721
Isozymes of human phosphofructokinase: identification and su... 		KEEP AS NON CORE
Summary: PFKM self-association into the M4 homotetramer, from the isozyme hybridization study.
Reason: Reflects M4 homotetramer formation; a genuine structural property but secondary to the catalytic function. Kept as non-core.
Supporting Evidence:
PMID:6444721
muscle and liver PFKs are distinct homotetramers-i.e., M(4) and L(4)
GO:0005829 cytosol
IEA
GO_REF:0000107 		ACCEPT
Summary: Cytosolic localization inferred by orthology (Ensembl Compara). This is the primary compartment of the glycolytic enzyme.
Reason: Correct and specific localization for a glycolytic enzyme, consistent with UniProt (Cytoplasm) and the Reactome cytosol annotation.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm
GO:0008443 phosphofructokinase activity
IEA
GO_REF:0000107 		ACCEPT
Summary: Broader parent term of 6-phosphofructokinase activity, transferred by orthology. Correct but less specific than GO:0003872.
Reason: The term is correct (a parent of the specific ATP-dependent 6-phosphofructokinase activity). Broader IEA annotations are acceptable; the specific term is also annotated.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
EC=2.7.1.11
GO:0042802 identical protein binding
IEA
GO_REF:0000107 		KEEP AS NON CORE
Summary: Identical protein binding transferred by orthology, reflecting homotetramer formation.
Reason: Consistent with M4 homotetramer assembly; genuine but non-core structural property.
Supporting Evidence:
PMID:6444721
muscle and liver PFKs are distinct homotetramers-i.e., M(4) and L(4)
GO:0061621 canonical glycolysis
IEA
GO_REF:0000107 		ACCEPT
Summary: Canonical glycolysis inferred by orthology. Core biological process for PFKM.
Reason: Correct - PFKM catalyzes the committed step of glycolysis. Duplicates the IBA/TAS annotations.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-
GO:0097228 sperm principal piece
IEA
GO_REF:0000107 		MARK AS OVER ANNOTATED
Summary: Localization to the sperm flagellum principal piece, transferred by orthology from mouse. Glycolytic enzymes are known to localize to the sperm principal piece in some species, but this is not a core localization of the human muscle enzyme and rests solely on Ensembl orthology transfer.
Reason: This is a species/cell-type-specific localization transferred electronically from mouse, not a defining compartment for the human muscle isozyme. Retained but flagged as over-annotated; the core localization is cytosol.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm
GO:0061621 canonical glycolysis
TAS
Reactome:R-HSA-70171 		ACCEPT
Summary: Reactome (Glycolysis) traceable assertion that PFKM participates in canonical glycolysis.
Reason: Correct core biological process, supported by an authoritative pathway database.
Supporting Evidence:
PMID:24817713
The main regulator of glycolysis, 6-phosphofructokinase (EC 2.7.1.11; Pfk), catalyzes the Mg-ATP-dependent formation of fructose 1,6-bisphosphate from fructose 6-phosphate
GO:0003872 6-phosphofructokinase activity
EXP
PMID:2960695
Characterization of the enzymatic defect in late-onset muscl... 		ACCEPT
Summary: Experimental (Reactome-sourced) support for 6-phosphofructokinase activity from a study characterizing the enzymatic defect in late-onset muscle PFK deficiency.
Reason: Core molecular function directly supported by experimental characterization of muscle PFK activity in patients.
Supporting Evidence:
PMID:2960695
The genetic lesion results in a total and partial loss of muscle and red cell PFK, respectively.
GO:0003872 6-phosphofructokinase activity
EXP
PMID:6444721
Isozymes of human phosphofructokinase: identification and su... 		ACCEPT
Summary: Experimental support for 6-phosphofructokinase activity from the human PFK isozyme characterization study.
Reason: Core molecular function; the muscle homotetramer M4 was characterized kinetically and immunologically as a phosphofructokinase.
Supporting Evidence:
PMID:6444721
Isozymes of human phosphofructokinase: identification and subunit structural characterization of a new system.
GO:0003872 6-phosphofructokinase activity
EXP
PMID:6451249
Isozymes of human phosphofructokinase in blood cells and cul... 		ACCEPT
Summary: Experimental (Reactome-sourced) support for 6-phosphofructokinase activity from a study of PFK isozymes in blood cells and cultured cell lines.
Reason: Core molecular function. This abstract-only record supports the trigenic (M/L/P) PFK system and the muscle-type enzyme activity; defer to the experimental annotation.
Supporting Evidence:
PMID:6451249
Isozymes of human phosphofructokinase in blood cells and cultured cell lines: molecular and genetic evidence for a trigenic system.
GO:0003872 6-phosphofructokinase activity
EXP
PMID:7825568
Functional expression of human mutant phosphofructokinase in... 		ACCEPT
Summary: Functional expression of human PFK-M in yeast established that PFKM confers 6-phosphofructokinase activity; a disease mutation (Gly209Asp) abolishes it.
Reason: Direct experimental evidence that PFKM is an active 6-phosphofructokinase, via reconstitution of activity in a yeast strain devoid of endogenous PFK.
Supporting Evidence:
PMID:7825568
Gly-209-mutated protein is completely inactive in the yeast system.
GO:0005945 6-phosphofructokinase complex
IPI
PMID:24817713
Crystallization and preliminary crystallographic analysis of... 		ACCEPT
Summary: ComplexPortal assertion that PFKM is part of the 6-phosphofructokinase complex, from the crystallization study of human muscle PFK (M4).
Reason: The active human muscle enzyme is a tetramer (M4); PFKM is a subunit of the 6-phosphofructokinase complex.
Supporting Evidence:
PMID:24817713
As in the structure of rmPfk, the physiological tetramer
GO:0006096 glycolytic process
NAS
PMID:24817713
Crystallization and preliminary crystallographic analysis of... 		ACCEPT
Summary: Non-traceable author statement (ComplexPortal) that PFKM is involved in glycolysis. Core biological process.
Reason: Correct - PFKM catalyzes the committed step of glycolysis; the paper explicitly describes it as the main regulator of glycolysis.
Supporting Evidence:
PMID:24817713
the main regulator of glycolysis
GO:0003872 6-phosphofructokinase activity
IMP
PMID:25796446
Aerobic glycolysis tunes YAP/TAZ transcriptional activity. 		ACCEPT
Summary: IMP for 6-phosphofructokinase activity from the YAP/TAZ aerobic glycolysis study, which manipulated PFK1 and glycolytic flux.
Reason: Core molecular function. The study depends on PFK1 glycolytic (6-phosphofructokinase) activity; the assignment to the muscle isozyme is consistent with the enzyme established function.
Supporting Evidence:
PMID:25796446
phosphofructokinase (PFK1), the enzyme regulating the first committed step of glycolysis
GO:0005515 protein binding
IPI
PMID:25796446
Aerobic glycolysis tunes YAP/TAZ transcriptional activity. 		MARK AS OVER ANNOTATED
Summary: IPI for protein binding (TEAD transcriptional cofactors) from the YAP/TAZ study. Uninformative "protein binding".
Reason: Bare "protein binding" is uninformative. The underlying PFK1-TEAD interaction is a moonlighting/context-specific function (aerobic glycolysis-YAP/TAZ signaling in proliferating cells), not the core muscle glycolytic role; flagged as over-annotated per policy.
Supporting Evidence:
PMID:25796446
binds the YAP/TAZ transcriptional cofactors TEADs
GO:0005634 nucleus
IDA
PMID:25796446
Aerobic glycolysis tunes YAP/TAZ transcriptional activity. 		MARK AS OVER ANNOTATED
Summary: Nuclear localization reported in the context of PFK1 promoting YAP/TAZ-TEAD transcriptional activity. A moonlighting, context-dependent localization, not the core cytosolic compartment of the glycolytic enzyme.
Reason: This is a context-specific moonlighting localization associated with transcriptional regulation in proliferating/cancer cells (CAFA IDA), not the primary compartment where PFKM performs its core glycolytic function. Retained but flagged as over-annotated; do not remove an experimental annotation.
Supporting Evidence:
PMID:25796446
phosphofructokinase (PFK1), the enzyme regulating the first committed step of glycolysis, binds the YAP/TAZ transcriptional cofactors TEADs
GO:0045944 positive regulation of transcription by RNA polymerase II
IMP
PMID:25796446
Aerobic glycolysis tunes YAP/TAZ transcriptional activity. 		MARK AS OVER ANNOTATED
Summary: PFK1 promotes YAP/TAZ-TEAD transcriptional activity, an indirect/moonlighting role linking glycolytic flux to gene transcription in proliferating cells.
Reason: This is a moonlighting, context-specific function tied to aerobic glycolysis and YAP/TAZ signaling, not the core function of the muscle glycolytic enzyme. Retained but flagged as over-annotated; the primary role is enzymatic.
Supporting Evidence:
PMID:25796446
promotes their functional and biochemical cooperation with YAP/TAZ
GO:0061615 glycolytic process through fructose-6-phosphate
IMP
PMID:25796446
Aerobic glycolysis tunes YAP/TAZ transcriptional activity. 		ACCEPT
Summary: Specific glycolysis term capturing the branch of glycolysis proceeding through fructose-6-phosphate - the exact step catalyzed by PFKM.
Reason: Accurately describes the PFKM role - it phosphorylates F6P, committing carbon to glycolysis through the fructose-6-phosphate branch.
Supporting Evidence:
PMID:25796446
phosphofructokinase (PFK1), the enzyme regulating the first committed step of glycolysis
GO:0005829 cytosol
TAS
Reactome:R-HSA-70467 		ACCEPT
Summary: Reactome traceable assertion that the PFK tetramer acts in the cytosol (PFK tetramer phosphorylates Fru(6)P).
Reason: Correct core localization for the glycolytic reaction, consistent with UniProt.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm
GO:0016324 apical plasma membrane
IDA
PMID:12649290
The a-subunit of the V-type H+-ATPase interacts with phospho... 		MARK AS OVER ANNOTATED
Summary: PFK-1 was co-immunolocalized with the V-ATPase a4 subunit at the apical membrane of alpha-intercalated cells in human kidney collecting duct - a specialized, cell-type-specific localization tied to a V-ATPase interaction.
Reason: This apical plasma membrane localization is specific to kidney alpha-intercalated cells and reflects the V-ATPase-PFK1 interaction that links proton pumping to glycolytic ATP supply; it is not a core localization of the muscle isozyme. Retained (experimental IDA) but flagged as over-annotated relative to the core cytosolic function.
Supporting Evidence:
PMID:12649290
PFK-1 co-immunolocalized with a4 in alpha-intercalated cells in the collecting ducts of human kidney.
GO:0003872 6-phosphofructokinase activity
ISS
GO_REF:0000024 		ACCEPT
Summary: Sequence-similarity transfer of 6-phosphofructokinase activity from an ortholog (P00511, rabbit muscle PFK). Correct core function.
Reason: The rabbit muscle enzyme is ~96% identical and the function is conserved; the assignment is correct and consistent with the experimental evidence.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
EC=2.7.1.11
GO:0003872 6-phosphofructokinase activity
IMP
PMID:6444532
The molecular mechanism of the inherited phosphofructokinase... 		ACCEPT
Summary: IMP for 6-phosphofructokinase activity - loss of the M subunit in Tarui disease abolishes muscle PFK activity, demonstrating PFKM is required for the activity.
Reason: Direct genetic evidence - in Tarui disease the M-type subunits are absent and muscle PFK activity is lost, establishing the PFKM role in conferring 6-phosphofructokinase activity.
Supporting Evidence:
PMID:6444532
in Tarui disease the M-type subunits are absent
GO:0003872 6-phosphofructokinase activity
IDA
PMID:6444721
Isozymes of human phosphofructokinase: identification and su... 		ACCEPT
Summary: Direct assay of muscle PFK (M4) activity in the isozyme characterization study.
Reason: Core molecular function directly demonstrated for the muscle homotetramer.
Supporting Evidence:
PMID:6444721
muscle and liver PFKs are distinct homotetramers-i.e., M(4) and L(4)
GO:0005945 6-phosphofructokinase complex
IDA
PMID:6444532
The molecular mechanism of the inherited phosphofructokinase... 		ACCEPT
Summary: Direct evidence that PFKM is part of the 6-phosphofructokinase complex, from analysis of PFK isozymes in Tarui disease.
Reason: Loss of M subunits removes M-containing tetramers, directly demonstrating PFKM is a constituent of the PFK complex.
Supporting Evidence:
PMID:6444532
consisted exclusively of the L4 isozyme
GO:0005945 6-phosphofructokinase complex
IDA
PMID:6444721
Isozymes of human phosphofructokinase: identification and su... 		ACCEPT
Summary: Direct evidence that PFKM assembles into the tetrameric PFK complex (M4 and M/L hybrids), from the isozyme hybridization study.
Reason: PFKM subunits polymerize into M4 and mixed tetramers; PFKM is part of the 6-phosphofructokinase complex.
Supporting Evidence:
PMID:6444721
result from the random polymerization of two distinct subunits, M (muscle type) and L (liver type), to form all possible tetrameters
GO:0006002 fructose 6-phosphate metabolic process
IMP
PMID:6444532
The molecular mechanism of the inherited phosphofructokinase... 		ACCEPT
Summary: IMP - loss of muscle PFK in Tarui disease blocks conversion of fructose 6-phosphate, implicating PFKM in F6P metabolism.
Reason: The metabolic crossover at PFK in patients demonstrates the PFKM role in consuming F6P.
Supporting Evidence:
PMID:6444532
a metabolic crossover point was found at the level of PFK
GO:0006002 fructose 6-phosphate metabolic process
IDA
PMID:6444721
Isozymes of human phosphofructokinase: identification and su... 		ACCEPT
Summary: Direct assay of muscle PFK acting on fructose 6-phosphate.
Reason: Consistent with PFKM catalyzing the F6P-consuming reaction; F6P metabolic process is directly supported.
Supporting Evidence:
PMID:6444721
the random polymerization of two distinct subunits, M (muscle type) and L (liver type)
GO:0006096 glycolytic process
IMP
PMID:6444532
The molecular mechanism of the inherited phosphofructokinase... 		ACCEPT
Summary: IMP for glycolytic process - the PFK block in Tarui disease impairs muscle glycolysis.
Reason: The metabolic crossover at PFK demonstrates the PFKM role in glycolysis; core biological process.
Supporting Evidence:
PMID:6444532
a metabolic crossover point was found at the level of PFK
GO:0019900 kinase binding
IPI
PMID:6444721
Isozymes of human phosphofructokinase: identification and su... 		KEEP AS NON CORE
Summary: IPI to PFKL (a kinase) reflecting hetero-oligomerization of the muscle subunit with the liver subunit to form hybrid PFK tetramers.
Reason: PFKM binds PFKL (itself a phosphofructokinase/kinase) during hybrid tetramer formation, so "kinase binding" is defensible and more informative than bare protein binding. However it is a structural corollary of complex assembly rather than the core catalytic function; kept as non-core.
Supporting Evidence:
PMID:6444721
the random polymerization of two distinct subunits, M (muscle type) and L (liver type)
GO:0046716 muscle cell cellular homeostasis
IMP
PMID:6444532
The molecular mechanism of the inherited phosphofructokinase... 		KEEP AS NON CORE
Summary: IMP linking PFKM to muscle cell homeostasis - PFK-M deficiency causes exertional myopathy, reflecting impaired energy metabolism in muscle.
Reason: This is a valid downstream physiological consequence of the enzymatic function (Tarui disease myopathy), but it is a phenotypic/organismal process rather than the core molecular role; kept as non-core.
Supporting Evidence:
PMID:6444532
the inherited erythrocyte PFK deficiency associated with myopathy and hemolysis (Tarui disease)
GO:0003872 6-phosphofructokinase activity
IDA
PMID:8780720
Isozyme analysis of human polymorphonuclear leukocyte phosph... 		ACCEPT
Summary: Direct assay of M-type PFK activity and kinetics in leukocyte isozyme analysis.
Reason: Core molecular function directly measured for the M-type isozyme (including its kinetic properties).
Supporting Evidence:
PMID:8780720
a 30% decrease was observed in the activity of M-type isozyme
GO:0005524 ATP binding
IDA
PMID:8780720
Isozyme analysis of human polymorphonuclear leukocyte phosph... 		ACCEPT
Summary: Direct evidence of ATP interaction with the M-type isozyme, inferred from its ATP-dependent kinetics and altered ATP inhibition.
Reason: ATP is the phosphoryl donor and an allosteric inhibitor of PFK; the study characterized ATP inhibition of the isozymes. Consistent with defined ATP-binding sites.
Supporting Evidence:
PMID:8780720
the decreased sensitivity to ATP inhibition
GO:0070061 fructose binding
IDA
PMID:8780720
Isozyme analysis of human polymorphonuclear leukocyte phosph... 		ACCEPT
Summary: Direct kinetic evidence of the M-type isozyme interaction with fructose 6-phosphate (its substrate), reported as altered F-6-P affinity.
Reason: The M-type isozyme affinity for fructose 6-phosphate was measured; binding of the fructose-phosphate substrate is intrinsic to the enzyme. Consistent with the more specific fructose-6-phosphate binding annotation.
Supporting Evidence:
PMID:8780720
lower affinity for F-6-P showed by the M-type isozyme
GO:0005515 protein binding
IPI
PMID:12649290
The a-subunit of the V-type H+-ATPase interacts with phospho... 		MARK AS OVER ANNOTATED
Summary: IPI to the V-ATPase a-subunit (ATP6V0A4/a4, Q9HBG4). "Protein binding" is uninformative; the interaction links PFK1 to V-ATPase-mediated proton transport in kidney.
Reason: The bare "protein binding" term is uninformative. The specific PFK1-V-ATPase a-subunit interaction is a kidney-specific regulatory link (coupling glycolysis to proton pumping) rather than a core function of the muscle enzyme; flagged as over-annotated per policy.
Supporting Evidence:
PMID:12649290
co-immunoprecipitation of a4 with PFK-1 from solubilized human kidney membrane proteins
GO:0006110 regulation of glycolytic process
IDA
file:human/PFKM/PFKM-uniprot.txt 		NEW
Summary: PFK-1 is the principal allosteric control point of glycolysis; PFKM activity is regulated by allosteric effectors (activated by AMP, ADP, fructose 2,6-bisphosphate; inhibited by ATP, citrate), making the enzyme a key regulator of glycolytic flux. Not present in the current GOA set but strongly supported by UniProt and the literature.
Reason: The regulatory (rate-limiting/allosteric control) role of PFKM is a defining feature of the enzyme and is captured in core_functions, but is not represented among the existing annotations. Proposed as a new annotation.
Supporting Evidence:
file:human/PFKM/PFKM-uniprot.txt
Allosterically activated by ADP, AMP, or fructose 2,6-bisphosphate, and allosterically inhibited by ATP or citrate.
PMID:24817713
the main regulator of glycolysis

Core Functions

Catalyzes the committed, rate-limiting step of glycolysis - the ATP-dependent phosphorylation of D-fructose 6-phosphate to fructose 1,6-bisphosphate - as the muscle isozyme of phosphofructokinase-1, acting in the cytosol as part of a tetrameric (M4) complex.

Molecular Function:
6-phosphofructokinase activity
Directly Involved In:
glycolytic process
Cellular Locations:
cytosol
In Complex:
6-phosphofructokinase complex
Supporting Evidence:
  • file:human/PFKM/PFKM-uniprot.txt
    Catalyzes the phosphorylation of D-fructose 6-phosphate to fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis.
  • PMID:7825568
    Gly-209-mutated protein is completely inactive in the yeast system.

Acts as a key allosteric control point of glycolytic flux; the enzyme is activated by AMP, ADP and fructose 2,6-bisphosphate and inhibited by ATP and citrate, and is described as the main regulator of glycolysis.

Molecular Function:
6-phosphofructokinase activity
Directly Involved In:
regulation of glycolytic process
Cellular Locations:
cytosol
Supporting Evidence:
  • file:human/PFKM/PFKM-uniprot.txt
    Allosterically activated by ADP, AMP, or fructose 2,6-bisphosphate, and allosterically inhibited by ATP or citrate.
  • PMID:24817713
    the main regulator of glycolysis

References

GO_REF:0000002
Gene Ontology annotation through association of InterPro records with GO terms
GO_REF:0000024
Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity
GO_REF:0000033
Annotation inferences using phylogenetic trees
GO_REF:0000107
Automatic transfer of experimentally verified manual GO annotation data to orthologs using Ensembl Compara
GO_REF:0000120
Combined Automated Annotation using Multiple IEA Methods
file:human/PFKM/PFKM-uniprot.txt
UniProtKB entry P08237 (PFKAM_HUMAN)
PMID:12649290
The a-subunit of the V-type H+-ATPase interacts with phosphofructokinase-1 in humans.
PMID:21988832
Toward an understanding of the protein interaction network of the human liver.
PMID:24817713
Crystallization and preliminary crystallographic analysis of human muscle phosphofructokinase, the main regulator of glycolysis.
PMID:25416956
A proteome-scale map of the human interactome network.
PMID:25796446
Aerobic glycolysis tunes YAP/TAZ transcriptional activity.
PMID:28514442
Architecture of the human interactome defines protein communities and disease networks.
PMID:2960695
Characterization of the enzymatic defect in late-onset muscle phosphofructokinase deficiency. New subtype of glycogen storage disease type VII.
PMID:33961781
Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.
PMID:36115835
Quantitative fragmentomics allow affinity mapping of interactomes.
PMID:6444532
The molecular mechanism of the inherited phosphofructokinase deficiency associated with hemolysis and myopathy.
PMID:6444721
Isozymes of human phosphofructokinase: identification and subunit structural characterization of a new system.
PMID:6451249
Isozymes of human phosphofructokinase in blood cells and cultured cell lines: molecular and genetic evidence for a trigenic system.
PMID:7825568
Functional expression of human mutant phosphofructokinase in yeast: genetic defects in French Canadian and Swiss patients with phosphofructokinase deficiency.
PMID:8780720
Isozyme analysis of human polymorphonuclear leukocyte phosphofructokinase from insulin resistant individuals.
Reactome:R-HSA-70171
Glycolysis
Reactome:R-HSA-70467
PFK tetramer phosphorylates Fru(6)P

📚 Additional Documentation

Notes

(PFKM-notes.md)

PFKM (human) review notes

UniProtKB: P08237. HGNC:8877. Muscle isoform of 6-phosphofructokinase (PFK-1), EC 2.7.1.11.

Core biology (from UniProt P08237 + literature)

  • Catalyzes the committed, rate-limiting step of glycolysis: ATP-dependent phosphorylation of
    D-fructose 6-phosphate to fructose 1,6-bisphosphate. [file:human/PFKM/PFKM-uniprot.txt "Catalyzes the phosphorylation of D-fructose 6-phosphate to fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis."]
  • Reaction: beta-D-fructose 6-phosphate + ATP = beta-D-fructose 1,6-bisphosphate + ADP + H+ (Rhea:16109, EC 2.7.1.11). Requires Mg2+ cofactor.
  • Allosteric enzyme: activated by ADP, AMP, or fructose 2,6-bisphosphate; inhibited by ATP or citrate.
    [file:human/PFKM/PFKM-uniprot.txt "Allosterically activated by ADP, AMP, or fructose 2,6-bisphosphate, and allosterically inhibited by ATP or citrate."]
  • Two-domain protein: N-terminal catalytic PFK domain 1 (res 2-390) and C-terminal regulatory PFK domain 2 (res 402-780); the C-terminal domain binds the F-2,6-BP allosteric activator.
  • Active enzyme is a tetramer built from three subunit types (PFKM/muscle, PFKL/liver, PFKP/platelet).
    Muscle = M4 homotetramer; erythrocytes = mixture M4, M3L, M2L2, ML3, L4. PMID:6444721
  • Cytoplasmic/cytosolic. [file:human/PFKM/PFKM-uniprot.txt "Cytoplasm"]

Disease

  • Glycogen storage disease type VII (Tarui disease, MIM:232800): exercise intolerance, muscle cramps,
    exertional myopathy and compensated hemolysis; caused by PFKM variants. M-subunit is absent/deficient;
    in erythrocytes only L4 remains. PMID:6444532 PMID:2960695 PMID:7825568

Key experimental evidence in cached publications

  • PMID:6444721 (Vora 1980, PNAS): five-membered PFK isozyme system from M and L subunits; muscle and
    liver PFKs are distinct homotetramers M4 and L4. Basis for the M4 complex + identical protein binding
  • kinase (PFKL) binding annotations. Abstract-only (full_text_available:false).
  • PMID:6444532 (Vora 1980, Blood): molecular basis of Tarui disease; M-subunits absent in patient.
    Basis for IMP MF/BP/muscle homeostasis annotations. Abstract-only.
  • PMID:7825568 (Raben 1995): functional expression of mutant PFK-M in yeast; Gly209Asp completely
    inactive. Direct evidence PFKM confers 6-PFK activity. Abstract-only.
  • PMID:2960695 (Vora 1987): late-onset PFK-M deficiency, "leaky" mutation. Abstract-only.
  • PMID:24817713 (Kloos 2014): crystallization of human muscle PFK, "the main regulator of glycolysis";
    catalyzes Mg-ATP-dependent formation of F1,6BP from F6P; full text available. Basis for M4 complex (ComplexPortal).
  • PMID:8780720 (Durante 1996): isozyme analysis of leukocyte PFK; kinetics incl. F-6-P affinity, ATP
    inhibition. Abstract-only. UniProt cites as IDA for 6-PFK activity, ATP binding, fructose binding.
  • PMID:25796446 (Enzo 2015, EMBO J): PFK1 binds YAP/TAZ cofactors TEADs and promotes their activity;
    aerobic glycolysis tunes YAP/TAZ. Source of nucleus/positive-reg-transcription/kinase-related IPIs (CAFA).
    Abstract-only. Moonlighting/context-dependent, not core muscle glycolytic function.
  • PMID:12649290 (Su 2003): a4/a1 subunit of V-ATPase interacts with PFK-1; PFK-1 co-immunolocalized at
    apical membrane of alpha-intercalated cells (kidney). Source of apical plasma membrane IDA + protein binding IPI.
    Abstract-only. Kidney-specific localization, non-core for muscle enzyme.

Interactome (bare protein binding IPIs — high-throughput)

  • PMID:21988832, 25416956, 28514442, 33961781, 36115835: proteome-scale interactome screens
    (liver PPI map, HuRI, BioPlex 2.0/3.0, fragmentomics/PDZ affinity). Many PDZ-domain partners in
    UniProt INTERACTION block (DLG1-4, MAGI1/2, SCRIB, PATJ, etc.) — mostly high-throughput; treat bare
    "protein binding" as uninformative -> MARK_AS_OVER_ANNOTATED (do not REMOVE per policy).

Annotation decisions summary

  • ACCEPT core: 6-PFK activity (all evidence codes), ATP binding, F6P binding, fructose binding,
    glycolytic process / canonical glycolysis / F6P & F1,6BP metabolic process, 6-PFK complex (M4),
    cytosol. phosphofructokinase activity (GO:0008443, parent of 0003872) ACCEPT (broader IEA is fine).
  • KEEP_AS_NON_CORE: muscle cell cellular homeostasis (IMP, downstream physiology); glycolytic process
    through fructose-6-phosphate (specific but fine).
  • MARK_AS_OVER_ANNOTATED: bare protein binding IPIs; identical protein binding & kinase binding
    (informative-ish but peripheral to core enzyme function — kept but non-core); apical plasma membrane
    (kidney-specific, IDA but not muscle enzyme core); membrane (IBA, is_active_in); nucleus + positive
    regulation of transcription by RNA pol II (moonlighting, CAFA IMP, context-specific/non-core);
    sperm principal piece (mouse-transfer IEA).

📄 View Raw YAML

 
id: P08237
gene_symbol: PFKM
product_type: PROTEIN
status: INITIALIZED
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: PFKM is the muscle isozyme of 6-phosphofructokinase (phosphofructokinase-1,
  PFK-1; EC 2.7.1.11), the enzyme that catalyzes the committed, rate-limiting step
  of glycolysis - the ATP-dependent phosphorylation of D-fructose 6-phosphate to
  fructose 1,6-bisphosphate, requiring Mg2+. It is a major allosteric control point
  of the pathway, activated by AMP, ADP and fructose 2,6-bisphosphate and inhibited
  by ATP and citrate. The active enzyme is a tetramer assembled from three subunit
  types - PFKM (muscle), PFKL (liver) and PFKP (platelet); skeletal muscle contains
  essentially the M4 homotetramer, whereas erythrocytes contain a mixture of M/L
  hybrids. Each subunit is a two-domain protein with an N-terminal catalytic domain
  and a C-terminal regulatory domain that binds allosteric effectors. PFKM acts in
  the cytosol. Loss-of-function variants in PFKM cause glycogen storage disease type
  VII (Tarui disease), characterized by exercise intolerance, muscle cramps, exertional
  myopathy and compensated hemolysis, reflecting the block of muscle glycolysis and
  its knock-on effects on glycogenolysis and erythrocyte metabolism.
alternative_products:
- name: '1'
  id: P08237-1
- name: '2'
  id: P08237-2
  sequence_note: VSP_004667
- name: '3'
  id: P08237-3
  sequence_note: VSP_046125
existing_annotations:
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: enables
  review:
    summary: Core molecular function - PFKM is a 6-phosphofructokinase that phosphorylates
      fructose 6-phosphate to fructose 1,6-bisphosphate. Phylogenetically inferred
      across the PFKA family and directly supported by experimental data on the human
      muscle enzyme.
    action: ACCEPT
    reason: This is the defining molecular function of PFKM, well supported across
      all evidence codes and by the UniProt catalytic activity annotation (EC 2.7.1.11).
      The IBA is at the correct level of specificity.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: Catalyzes the phosphorylation of D-fructose 6-phosphate to
        fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis.
- term:
    id: GO:0006002
    label: fructose 6-phosphate metabolic process
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: Fructose 6-phosphate is the substrate of PFKM, so participation in F6P
      metabolism is a direct consequence of the catalytic activity.
    action: ACCEPT
    reason: Consistent with the reaction catalyzed; F6P is consumed by PFKM in the
      committed step of glycolysis.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: Catalyzes the phosphorylation of D-fructose 6-phosphate to
        fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis.
- term:
    id: GO:0030388
    label: fructose 1,6-bisphosphate metabolic process
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: Fructose 1,6-bisphosphate is the product of the PFKM-catalyzed reaction,
      so PFKM participates in its metabolism (production).
    action: ACCEPT
    reason: Directly reflects the product of the catalytic reaction.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: Catalyzes the phosphorylation of D-fructose 6-phosphate to
        fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis.
- term:
    id: GO:0061621
    label: canonical glycolysis
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: PFKM catalyzes the committed step of glycolysis and is a canonical component
      of the pathway.
    action: ACCEPT
    reason: Central role in glycolysis, phylogenetically conserved and experimentally
      established. Appropriate biological process term.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-
    - reference_id: PMID:24817713
      supporting_text: "The main regulator of glycolysis, 6-phosphofructokinase (EC\
        \ 2.7.1.11; Pfk), catalyzes the Mg-ATP-dependent formation of fructose 1,6-bisphosphate\
        \ from fructose 6-phosphate"
- term:
    id: GO:0005945
    label: 6-phosphofructokinase complex
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: part_of
  review:
    summary: The active PFK enzyme is a tetramer; in muscle it is the M4 homotetramer.
      PFKM is a subunit of the 6-phosphofructokinase complex.
    action: ACCEPT
    reason: Well supported - the enzyme functions as a tetramer composed of PFKM,
      PFKL and PFKP subunits, and PFKM is part of this complex.
    supported_by:
    - reference_id: PMID:6444721
      supporting_text: These data demonstrate that muscle and liver PFKs are distinct
        homotetramers-i.e., M(4) and L(4), respectively
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: Phosphofructokinase (PFK) enzyme functions as a tetramer composed
        of different combinations
- term:
    id: GO:0016020
    label: membrane
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: is_active_in
  review:
    summary: An IBA "is_active_in membrane" annotation. PFKM is a soluble cytosolic
      enzyme; membrane association is at best transient/regulatory (e.g. actin, caveolin,
      V-ATPase in specific cell types), not the site of its core catalytic activity.
    action: MARK_AS_OVER_ANNOTATED
    reason: The generic "membrane" location does not represent the core cytosolic
      localization of this glycolytic enzyme. Any membrane association is peripheral
      and cell-type-specific rather than a defining compartment. The cytosol annotations
      capture the primary localization.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: "SUBCELLULAR LOCATION: Cytoplasm"
- term:
    id: GO:0070095
    label: fructose-6-phosphate binding
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: enables
  review:
    summary: PFKM binds fructose 6-phosphate as its phosphoacceptor substrate. Substrate
      binding is intrinsic to the enzyme mechanism.
    action: ACCEPT
    reason: Directly supported - F6P is the substrate and specific F6P/substrate binding
      residues are annotated in the structure. Kinetic F-6-P affinity has been measured
      for the M-type isozyme.
    supported_by:
    - reference_id: PMID:8780720
      supporting_text: lower affinity for F-6-P showed by the M-type isozyme
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: enables
  review:
    summary: Electronic assertion of the core 6-phosphofructokinase activity via UniRule/InterPro
      and the RHEA:16109 / EC 2.7.1.11 mapping.
    action: ACCEPT
    reason: Correct core molecular function, consistent with the experimental and
      IBA annotations of the same term.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: "EC=2.7.1.11"
- term:
    id: GO:0005524
    label: ATP binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  review:
    summary: PFKM uses ATP as the phosphoryl donor and has defined ATP-binding residues;
      ATP binding is intrinsic to the kinase reaction.
    action: ACCEPT
    reason: Well supported - ATP is a co-substrate; UniProt annotates multiple ATP-binding
      sites and ATP additionally acts as an allosteric inhibitor. Confirmed experimentally.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: '/ligand="ATP"'
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: located_in
  review:
    summary: PFKM is a cytoplasmic/cytosolic enzyme. Consistent with the UniProt subcellular
      location and the cytosol annotations.
    action: ACCEPT
    reason: Correct localization, though the more specific "cytosol" term is preferable
      and is also annotated. Accepting the broader parent as-is.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: "SUBCELLULAR LOCATION: Cytoplasm"
- term:
    id: GO:0006002
    label: fructose 6-phosphate metabolic process
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: involved_in
  review:
    summary: Electronic (InterPro) inference of F6P metabolism, consistent with the
      enzyme substrate.
    action: ACCEPT
    reason: Correct - F6P is the substrate consumed by PFKM. Duplicates the IBA and
      experimental annotations of the same term.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: Catalyzes the phosphorylation of D-fructose 6-phosphate to
        fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis.
- term:
    id: GO:0006096
    label: glycolytic process
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: involved_in
  review:
    summary: Electronic inference (UniRule/InterPro/UniPathway) that PFKM participates
      in glycolysis. This is the core biological process.
    action: ACCEPT
    reason: PFKM catalyzes the committed step of glycolysis; the annotation is correct
      and at an appropriate level.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:21988832
  qualifier: enables
  review:
    summary: High-throughput protein interaction annotation from a proteome-scale
      human liver interactome map. "Protein binding" is uninformative about molecular
      function.
    action: MARK_AS_OVER_ANNOTATED
    reason: The bare "protein binding" term conveys no specific functional information
      and derives from a large-scale interactome screen. Per curation policy such
      IPIs are marked as over-annotated rather than removed; the informative functions
      (kinase activity, complex assembly) are captured elsewhere.
    supported_by:
    - reference_id: PMID:21988832
      supporting_text: Proteome-scale protein interaction maps are available for many
        organisms
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:25416956
  qualifier: enables
  review:
    summary: High-throughput binary interaction from a proteome-scale human interactome
      (HuRI) map. Uninformative "protein binding".
    action: MARK_AS_OVER_ANNOTATED
    reason: Bare "protein binding" from a systematic interactome screen adds no specific
      functional detail; retained but flagged as over-annotated per policy.
    supported_by:
    - reference_id: PMID:25416956
      supporting_text: Here, we describe a systematic map of
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:28514442
  qualifier: enables
  review:
    summary: High-throughput interaction from BioPlex 2.0 affinity-purification mass
      spectrometry. Uninformative "protein binding".
    action: MARK_AS_OVER_ANNOTATED
    reason: Bare "protein binding" from a large-scale AP-MS interactome dataset; no
      specific molecular function conveyed. Flagged as over-annotated per policy.
    supported_by:
    - reference_id: PMID:28514442
      supporting_text: we present BioPlex 2.0
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:33961781
  qualifier: enables
  review:
    summary: High-throughput interaction from BioPlex 3.0 affinity-purification networks.
      Uninformative "protein binding".
    action: MARK_AS_OVER_ANNOTATED
    reason: Bare "protein binding" from a proteome-scale AP-MS interactome; no specific
      function conveyed. Flagged as over-annotated per policy.
    supported_by:
    - reference_id: PMID:33961781
      supporting_text: Through affinity-purification
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:36115835
  qualifier: enables
  review:
    summary: Interactions mapped by quantitative fragmentomics/affinity mapping (many
      PDZ-domain partners). Uninformative "protein binding".
    action: MARK_AS_OVER_ANNOTATED
    reason: Bare "protein binding" from a high-throughput affinity-mapping study;
      the many PDZ partners are unlikely to reflect the core muscle glycolytic function.
      Flagged as over-annotated per policy.
    supported_by:
    - reference_id: PMID:36115835
      supporting_text: Quantitative fragmentomics allow affinity mapping of interactomes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:6444721
  qualifier: enables
  review:
    summary: IPI to PFKL (P17858) from the isozyme hybridization study. The specific
      biology (M/L subunit tetramerization) is better captured by the complex and
      identical/kinase binding annotations. Bare "protein binding" is uninformative.
    action: MARK_AS_OVER_ANNOTATED
    reason: While the underlying interaction (PFKM-PFKL) is real and biologically
      meaningful for hybrid tetramer formation, the generic "protein binding" term
      is uninformative; the same paper supports the more specific 6-phosphofructokinase
      complex and kinase binding annotations. Flagged as over-annotated per policy.
    supported_by:
    - reference_id: PMID:6444721
      supporting_text: These multimolecular forms result from the random polymerization
        of two distinct subunits, M (muscle type) and L (liver type)
- term:
    id: GO:0042802
    label: identical protein binding
  evidence_type: IPI
  original_reference_id: PMID:25416956
  qualifier: enables
  review:
    summary: PFKM self-association (M4 homotetramer). Identical protein binding reflects
      the homotetrameric assembly of the muscle enzyme.
    action: KEEP_AS_NON_CORE
    reason: The muscle enzyme is an M4 homotetramer, so PFKM binds identical subunits.
      This is a real, informative property, but it is a structural corollary of complex
      assembly rather than the primary catalytic function; kept as non-core.
    supported_by:
    - reference_id: PMID:6444721
      supporting_text: muscle and liver PFKs are distinct homotetramers-i.e., M(4)
        and L(4)
- term:
    id: GO:0042802
    label: identical protein binding
  evidence_type: IPI
  original_reference_id: PMID:6444721
  qualifier: enables
  review:
    summary: PFKM self-association into the M4 homotetramer, from the isozyme hybridization
      study.
    action: KEEP_AS_NON_CORE
    reason: Reflects M4 homotetramer formation; a genuine structural property but
      secondary to the catalytic function. Kept as non-core.
    supported_by:
    - reference_id: PMID:6444721
      supporting_text: muscle and liver PFKs are distinct homotetramers-i.e., M(4)
        and L(4)
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  qualifier: located_in
  review:
    summary: Cytosolic localization inferred by orthology (Ensembl Compara). This
      is the primary compartment of the glycolytic enzyme.
    action: ACCEPT
    reason: Correct and specific localization for a glycolytic enzyme, consistent
      with UniProt (Cytoplasm) and the Reactome cytosol annotation.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: "SUBCELLULAR LOCATION: Cytoplasm"
- term:
    id: GO:0008443
    label: phosphofructokinase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  qualifier: enables
  review:
    summary: Broader parent term of 6-phosphofructokinase activity, transferred by
      orthology. Correct but less specific than GO:0003872.
    action: ACCEPT
    reason: The term is correct (a parent of the specific ATP-dependent 6-phosphofructokinase
      activity). Broader IEA annotations are acceptable; the specific term is also
      annotated.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: "EC=2.7.1.11"
- term:
    id: GO:0042802
    label: identical protein binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  qualifier: enables
  review:
    summary: Identical protein binding transferred by orthology, reflecting homotetramer
      formation.
    action: KEEP_AS_NON_CORE
    reason: Consistent with M4 homotetramer assembly; genuine but non-core structural
      property.
    supported_by:
    - reference_id: PMID:6444721
      supporting_text: muscle and liver PFKs are distinct homotetramers-i.e., M(4)
        and L(4)
- term:
    id: GO:0061621
    label: canonical glycolysis
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  qualifier: involved_in
  review:
    summary: Canonical glycolysis inferred by orthology. Core biological process for
      PFKM.
    action: ACCEPT
    reason: Correct - PFKM catalyzes the committed step of glycolysis. Duplicates
      the IBA/TAS annotations.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-
- term:
    id: GO:0097228
    label: sperm principal piece
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  qualifier: located_in
  review:
    summary: Localization to the sperm flagellum principal piece, transferred by orthology
      from mouse. Glycolytic enzymes are known to localize to the sperm principal
      piece in some species, but this is not a core localization of the human muscle
      enzyme and rests solely on Ensembl orthology transfer.
    action: MARK_AS_OVER_ANNOTATED
    reason: This is a species/cell-type-specific localization transferred electronically
      from mouse, not a defining compartment for the human muscle isozyme. Retained
      but flagged as over-annotated; the core localization is cytosol.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: "SUBCELLULAR LOCATION: Cytoplasm"
- term:
    id: GO:0061621
    label: canonical glycolysis
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-70171
  qualifier: involved_in
  review:
    summary: Reactome (Glycolysis) traceable assertion that PFKM participates in canonical
      glycolysis.
    action: ACCEPT
    reason: Correct core biological process, supported by an authoritative pathway
      database.
    supported_by:
    - reference_id: PMID:24817713
      supporting_text: "The main regulator of glycolysis, 6-phosphofructokinase (EC\
        \ 2.7.1.11; Pfk), catalyzes the Mg-ATP-dependent formation of fructose 1,6-bisphosphate\
        \ from fructose 6-phosphate"
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: EXP
  original_reference_id: PMID:2960695
  qualifier: enables
  review:
    summary: Experimental (Reactome-sourced) support for 6-phosphofructokinase activity
      from a study characterizing the enzymatic defect in late-onset muscle PFK deficiency.
    action: ACCEPT
    reason: Core molecular function directly supported by experimental characterization
      of muscle PFK activity in patients.
    supported_by:
    - reference_id: PMID:2960695
      supporting_text: The genetic lesion results in a total and partial loss of muscle
        and red cell PFK, respectively.
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: EXP
  original_reference_id: PMID:6444721
  qualifier: enables
  review:
    summary: Experimental support for 6-phosphofructokinase activity from the human
      PFK isozyme characterization study.
    action: ACCEPT
    reason: Core molecular function; the muscle homotetramer M4 was characterized
      kinetically and immunologically as a phosphofructokinase.
    supported_by:
    - reference_id: PMID:6444721
      supporting_text: "Isozymes of human phosphofructokinase: identification and\
        \ subunit structural characterization of a new system."
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: EXP
  original_reference_id: PMID:6451249
  qualifier: enables
  review:
    summary: Experimental (Reactome-sourced) support for 6-phosphofructokinase activity
      from a study of PFK isozymes in blood cells and cultured cell lines.
    action: ACCEPT
    reason: Core molecular function. This abstract-only record supports the trigenic
      (M/L/P) PFK system and the muscle-type enzyme activity; defer to the experimental
      annotation.
    supported_by:
    - reference_id: PMID:6451249
      supporting_text: "Isozymes of human phosphofructokinase in blood cells and cultured\
        \ cell lines: molecular and genetic evidence for a trigenic system."
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: EXP
  original_reference_id: PMID:7825568
  qualifier: enables
  review:
    summary: Functional expression of human PFK-M in yeast established that PFKM confers
      6-phosphofructokinase activity; a disease mutation (Gly209Asp) abolishes it.
    action: ACCEPT
    reason: Direct experimental evidence that PFKM is an active 6-phosphofructokinase,
      via reconstitution of activity in a yeast strain devoid of endogenous PFK.
    supported_by:
    - reference_id: PMID:7825568
      supporting_text: Gly-209-mutated protein is completely inactive in the yeast
        system.
- term:
    id: GO:0005945
    label: 6-phosphofructokinase complex
  evidence_type: IPI
  original_reference_id: PMID:24817713
  qualifier: part_of
  review:
    summary: ComplexPortal assertion that PFKM is part of the 6-phosphofructokinase
      complex, from the crystallization study of human muscle PFK (M4).
    action: ACCEPT
    reason: The active human muscle enzyme is a tetramer (M4); PFKM is a subunit of
      the 6-phosphofructokinase complex.
    supported_by:
    - reference_id: PMID:24817713
      supporting_text: As in the structure of rmPfk, the physiological tetramer
- term:
    id: GO:0006096
    label: glycolytic process
  evidence_type: NAS
  original_reference_id: PMID:24817713
  qualifier: involved_in
  review:
    summary: Non-traceable author statement (ComplexPortal) that PFKM is involved
      in glycolysis. Core biological process.
    action: ACCEPT
    reason: Correct - PFKM catalyzes the committed step of glycolysis; the paper explicitly
      describes it as the main regulator of glycolysis.
    supported_by:
    - reference_id: PMID:24817713
      supporting_text: the main regulator of glycolysis
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: IMP
  original_reference_id: PMID:25796446
  qualifier: enables
  review:
    summary: IMP for 6-phosphofructokinase activity from the YAP/TAZ aerobic glycolysis
      study, which manipulated PFK1 and glycolytic flux.
    action: ACCEPT
    reason: Core molecular function. The study depends on PFK1 glycolytic (6-phosphofructokinase)
      activity; the assignment to the muscle isozyme is consistent with the enzyme
      established function.
    supported_by:
    - reference_id: PMID:25796446
      supporting_text: phosphofructokinase (PFK1), the enzyme regulating the first
        committed step of glycolysis
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:25796446
  qualifier: enables
  review:
    summary: IPI for protein binding (TEAD transcriptional cofactors) from the YAP/TAZ
      study. Uninformative "protein binding".
    action: MARK_AS_OVER_ANNOTATED
    reason: Bare "protein binding" is uninformative. The underlying PFK1-TEAD interaction
      is a moonlighting/context-specific function (aerobic glycolysis-YAP/TAZ signaling
      in proliferating cells), not the core muscle glycolytic role; flagged as over-annotated
      per policy.
    supported_by:
    - reference_id: PMID:25796446
      supporting_text: binds the YAP/TAZ transcriptional cofactors TEADs
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IDA
  original_reference_id: PMID:25796446
  qualifier: located_in
  review:
    summary: Nuclear localization reported in the context of PFK1 promoting YAP/TAZ-TEAD
      transcriptional activity. A moonlighting, context-dependent localization, not
      the core cytosolic compartment of the glycolytic enzyme.
    action: MARK_AS_OVER_ANNOTATED
    reason: This is a context-specific moonlighting localization associated with transcriptional
      regulation in proliferating/cancer cells (CAFA IDA), not the primary compartment
      where PFKM performs its core glycolytic function. Retained but flagged as over-annotated;
      do not remove an experimental annotation.
    supported_by:
    - reference_id: PMID:25796446
      supporting_text: phosphofructokinase (PFK1), the enzyme regulating the first
        committed step of glycolysis, binds the YAP/TAZ transcriptional cofactors
        TEADs
- term:
    id: GO:0045944
    label: positive regulation of transcription by RNA polymerase II
  evidence_type: IMP
  original_reference_id: PMID:25796446
  qualifier: involved_in
  review:
    summary: PFK1 promotes YAP/TAZ-TEAD transcriptional activity, an indirect/moonlighting
      role linking glycolytic flux to gene transcription in proliferating cells.
    action: MARK_AS_OVER_ANNOTATED
    reason: This is a moonlighting, context-specific function tied to aerobic glycolysis
      and YAP/TAZ signaling, not the core function of the muscle glycolytic enzyme.
      Retained but flagged as over-annotated; the primary role is enzymatic.
    supported_by:
    - reference_id: PMID:25796446
      supporting_text: promotes their functional and biochemical cooperation with
        YAP/TAZ
- term:
    id: GO:0061615
    label: glycolytic process through fructose-6-phosphate
  evidence_type: IMP
  original_reference_id: PMID:25796446
  qualifier: involved_in
  review:
    summary: Specific glycolysis term capturing the branch of glycolysis proceeding
      through fructose-6-phosphate - the exact step catalyzed by PFKM.
    action: ACCEPT
    reason: Accurately describes the PFKM role - it phosphorylates F6P, committing
      carbon to glycolysis through the fructose-6-phosphate branch.
    supported_by:
    - reference_id: PMID:25796446
      supporting_text: phosphofructokinase (PFK1), the enzyme regulating the first
        committed step of glycolysis
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-70467
  qualifier: located_in
  review:
    summary: Reactome traceable assertion that the PFK tetramer acts in the cytosol
      (PFK tetramer phosphorylates Fru(6)P).
    action: ACCEPT
    reason: Correct core localization for the glycolytic reaction, consistent with
      UniProt.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: "SUBCELLULAR LOCATION: Cytoplasm"
- term:
    id: GO:0016324
    label: apical plasma membrane
  evidence_type: IDA
  original_reference_id: PMID:12649290
  qualifier: located_in
  review:
    summary: PFK-1 was co-immunolocalized with the V-ATPase a4 subunit at the apical
      membrane of alpha-intercalated cells in human kidney collecting duct - a specialized,
      cell-type-specific localization tied to a V-ATPase interaction.
    action: MARK_AS_OVER_ANNOTATED
    reason: This apical plasma membrane localization is specific to kidney alpha-intercalated
      cells and reflects the V-ATPase-PFK1 interaction that links proton pumping to
      glycolytic ATP supply; it is not a core localization of the muscle isozyme.
      Retained (experimental IDA) but flagged as over-annotated relative to the core
      cytosolic function.
    supported_by:
    - reference_id: PMID:12649290
      supporting_text: PFK-1 co-immunolocalized with a4 in alpha-intercalated cells
        in the collecting ducts of human kidney.
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  qualifier: enables
  review:
    summary: Sequence-similarity transfer of 6-phosphofructokinase activity from an
      ortholog (P00511, rabbit muscle PFK). Correct core function.
    action: ACCEPT
    reason: The rabbit muscle enzyme is ~96% identical and the function is conserved;
      the assignment is correct and consistent with the experimental evidence.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: "EC=2.7.1.11"
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: IMP
  original_reference_id: PMID:6444532
  qualifier: enables
  review:
    summary: IMP for 6-phosphofructokinase activity - loss of the M subunit in Tarui
      disease abolishes muscle PFK activity, demonstrating PFKM is required for the
      activity.
    action: ACCEPT
    reason: Direct genetic evidence - in Tarui disease the M-type subunits are absent
      and muscle PFK activity is lost, establishing the PFKM role in conferring 6-phosphofructokinase
      activity.
    supported_by:
    - reference_id: PMID:6444532
      supporting_text: in Tarui disease the M-type subunits are absent
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: IDA
  original_reference_id: PMID:6444721
  qualifier: enables
  review:
    summary: Direct assay of muscle PFK (M4) activity in the isozyme characterization
      study.
    action: ACCEPT
    reason: Core molecular function directly demonstrated for the muscle homotetramer.
    supported_by:
    - reference_id: PMID:6444721
      supporting_text: muscle and liver PFKs are distinct homotetramers-i.e., M(4)
        and L(4)
- term:
    id: GO:0005945
    label: 6-phosphofructokinase complex
  evidence_type: IDA
  original_reference_id: PMID:6444532
  qualifier: part_of
  review:
    summary: Direct evidence that PFKM is part of the 6-phosphofructokinase complex,
      from analysis of PFK isozymes in Tarui disease.
    action: ACCEPT
    reason: Loss of M subunits removes M-containing tetramers, directly demonstrating
      PFKM is a constituent of the PFK complex.
    supported_by:
    - reference_id: PMID:6444532
      supporting_text: consisted exclusively of the L4 isozyme
- term:
    id: GO:0005945
    label: 6-phosphofructokinase complex
  evidence_type: IDA
  original_reference_id: PMID:6444721
  qualifier: part_of
  review:
    summary: Direct evidence that PFKM assembles into the tetrameric PFK complex (M4
      and M/L hybrids), from the isozyme hybridization study.
    action: ACCEPT
    reason: PFKM subunits polymerize into M4 and mixed tetramers; PFKM is part of
      the 6-phosphofructokinase complex.
    supported_by:
    - reference_id: PMID:6444721
      supporting_text: result from the random polymerization of two distinct subunits,
        M (muscle type) and L (liver type), to form all possible tetrameters
- term:
    id: GO:0006002
    label: fructose 6-phosphate metabolic process
  evidence_type: IMP
  original_reference_id: PMID:6444532
  qualifier: involved_in
  review:
    summary: IMP - loss of muscle PFK in Tarui disease blocks conversion of fructose
      6-phosphate, implicating PFKM in F6P metabolism.
    action: ACCEPT
    reason: The metabolic crossover at PFK in patients demonstrates the PFKM role
      in consuming F6P.
    supported_by:
    - reference_id: PMID:6444532
      supporting_text: a metabolic crossover point was found at the level of PFK
- term:
    id: GO:0006002
    label: fructose 6-phosphate metabolic process
  evidence_type: IDA
  original_reference_id: PMID:6444721
  qualifier: involved_in
  review:
    summary: Direct assay of muscle PFK acting on fructose 6-phosphate.
    action: ACCEPT
    reason: Consistent with PFKM catalyzing the F6P-consuming reaction; F6P metabolic
      process is directly supported.
    supported_by:
    - reference_id: PMID:6444721
      supporting_text: the random polymerization of two distinct subunits, M (muscle
        type) and L (liver type)
- term:
    id: GO:0006096
    label: glycolytic process
  evidence_type: IMP
  original_reference_id: PMID:6444532
  qualifier: involved_in
  review:
    summary: IMP for glycolytic process - the PFK block in Tarui disease impairs muscle
      glycolysis.
    action: ACCEPT
    reason: The metabolic crossover at PFK demonstrates the PFKM role in glycolysis;
      core biological process.
    supported_by:
    - reference_id: PMID:6444532
      supporting_text: a metabolic crossover point was found at the level of PFK
- term:
    id: GO:0019900
    label: kinase binding
  evidence_type: IPI
  original_reference_id: PMID:6444721
  qualifier: enables
  review:
    summary: IPI to PFKL (a kinase) reflecting hetero-oligomerization of the muscle
      subunit with the liver subunit to form hybrid PFK tetramers.
    action: KEEP_AS_NON_CORE
    reason: PFKM binds PFKL (itself a phosphofructokinase/kinase) during hybrid tetramer
      formation, so "kinase binding" is defensible and more informative than bare
      protein binding. However it is a structural corollary of complex assembly rather
      than the core catalytic function; kept as non-core.
    supported_by:
    - reference_id: PMID:6444721
      supporting_text: the random polymerization of two distinct subunits, M (muscle
        type) and L (liver type)
- term:
    id: GO:0046716
    label: muscle cell cellular homeostasis
  evidence_type: IMP
  original_reference_id: PMID:6444532
  qualifier: involved_in
  review:
    summary: IMP linking PFKM to muscle cell homeostasis - PFK-M deficiency causes
      exertional myopathy, reflecting impaired energy metabolism in muscle.
    action: KEEP_AS_NON_CORE
    reason: This is a valid downstream physiological consequence of the enzymatic
      function (Tarui disease myopathy), but it is a phenotypic/organismal process
      rather than the core molecular role; kept as non-core.
    supported_by:
    - reference_id: PMID:6444532
      supporting_text: the inherited erythrocyte PFK deficiency associated with myopathy
        and hemolysis (Tarui disease)
- term:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  evidence_type: IDA
  original_reference_id: PMID:8780720
  qualifier: enables
  review:
    summary: Direct assay of M-type PFK activity and kinetics in leukocyte isozyme
      analysis.
    action: ACCEPT
    reason: Core molecular function directly measured for the M-type isozyme (including
      its kinetic properties).
    supported_by:
    - reference_id: PMID:8780720
      supporting_text: a 30% decrease was observed in the activity of M-type isozyme
- term:
    id: GO:0005524
    label: ATP binding
  evidence_type: IDA
  original_reference_id: PMID:8780720
  qualifier: enables
  review:
    summary: Direct evidence of ATP interaction with the M-type isozyme, inferred
      from its ATP-dependent kinetics and altered ATP inhibition.
    action: ACCEPT
    reason: ATP is the phosphoryl donor and an allosteric inhibitor of PFK; the study
      characterized ATP inhibition of the isozymes. Consistent with defined ATP-binding
      sites.
    supported_by:
    - reference_id: PMID:8780720
      supporting_text: the decreased sensitivity to ATP inhibition
- term:
    id: GO:0070061
    label: fructose binding
  evidence_type: IDA
  original_reference_id: PMID:8780720
  qualifier: enables
  review:
    summary: Direct kinetic evidence of the M-type isozyme interaction with fructose
      6-phosphate (its substrate), reported as altered F-6-P affinity.
    action: ACCEPT
    reason: The M-type isozyme affinity for fructose 6-phosphate was measured; binding
      of the fructose-phosphate substrate is intrinsic to the enzyme. Consistent with
      the more specific fructose-6-phosphate binding annotation.
    supported_by:
    - reference_id: PMID:8780720
      supporting_text: lower affinity for F-6-P showed by the M-type isozyme
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:12649290
  qualifier: enables
  review:
    summary: IPI to the V-ATPase a-subunit (ATP6V0A4/a4, Q9HBG4). "Protein binding"
      is uninformative; the interaction links PFK1 to V-ATPase-mediated proton transport
      in kidney.
    action: MARK_AS_OVER_ANNOTATED
    reason: The bare "protein binding" term is uninformative. The specific PFK1-V-ATPase
      a-subunit interaction is a kidney-specific regulatory link (coupling glycolysis
      to proton pumping) rather than a core function of the muscle enzyme; flagged
      as over-annotated per policy.
    supported_by:
    - reference_id: PMID:12649290
      supporting_text: co-immunoprecipitation of a4 with PFK-1 from solubilized human
        kidney membrane proteins
- term:
    id: GO:0006110
    label: regulation of glycolytic process
  evidence_type: IDA
  original_reference_id: file:human/PFKM/PFKM-uniprot.txt
  qualifier: involved_in
  review:
    summary: PFK-1 is the principal allosteric control point of glycolysis; PFKM activity
      is regulated by allosteric effectors (activated by AMP, ADP, fructose 2,6-bisphosphate;
      inhibited by ATP, citrate), making the enzyme a key regulator of glycolytic
      flux. Not present in the current GOA set but strongly supported by UniProt and
      the literature.
    action: NEW
    reason: The regulatory (rate-limiting/allosteric control) role of PFKM is a defining
      feature of the enzyme and is captured in core_functions, but is not represented
      among the existing annotations. Proposed as a new annotation.
    supported_by:
    - reference_id: file:human/PFKM/PFKM-uniprot.txt
      supporting_text: Allosterically activated by ADP, AMP, or fructose 2,6-bisphosphate,
        and allosterically inhibited by ATP or citrate.
    - reference_id: PMID:24817713
      supporting_text: the main regulator of glycolysis
core_functions:
- description: Catalyzes the committed, rate-limiting step of glycolysis - the ATP-dependent
    phosphorylation of D-fructose 6-phosphate to fructose 1,6-bisphosphate - as the
    muscle isozyme of phosphofructokinase-1, acting in the cytosol as part of a tetrameric
    (M4) complex.
  molecular_function:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  directly_involved_in:
  - id: GO:0006096
    label: glycolytic process
  in_complex:
    id: GO:0005945
    label: 6-phosphofructokinase complex
  locations:
  - id: GO:0005829
    label: cytosol
  supported_by:
  - reference_id: file:human/PFKM/PFKM-uniprot.txt
    supporting_text: Catalyzes the phosphorylation of D-fructose 6-phosphate to fructose
      1,6-bisphosphate by ATP, the first committing step of glycolysis.
  - reference_id: PMID:7825568
    supporting_text: Gly-209-mutated protein is completely inactive in the yeast system.
- description: Acts as a key allosteric control point of glycolytic flux; the enzyme
    is activated by AMP, ADP and fructose 2,6-bisphosphate and inhibited by ATP and
    citrate, and is described as the main regulator of glycolysis.
  molecular_function:
    id: GO:0003872
    label: 6-phosphofructokinase activity
  directly_involved_in:
  - id: GO:0006110
    label: regulation of glycolytic process
  locations:
  - id: GO:0005829
    label: cytosol
  supported_by:
  - reference_id: file:human/PFKM/PFKM-uniprot.txt
    supporting_text: Allosterically activated by ADP, AMP, or fructose 2,6-bisphosphate,
      and allosterically inhibited by ATP or citrate.
  - reference_id: PMID:24817713
    supporting_text: the main regulator of glycolysis
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO
    terms
  findings: []
- id: GO_REF:0000024
  title: Manual transfer of experimentally-verified manual GO annotation data to orthologs
    by curator judgment of sequence similarity
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000107
  title: Automatic transfer of experimentally verified manual GO annotation data to
    orthologs using Ensembl Compara
  findings: []
- id: GO_REF:0000120
  title: Combined Automated Annotation using Multiple IEA Methods
  findings: []
- id: file:human/PFKM/PFKM-uniprot.txt
  title: UniProtKB entry P08237 (PFKAM_HUMAN)
  findings: []
- id: PMID:12649290
  title: The a-subunit of the V-type H+-ATPase interacts with phosphofructokinase-1
    in humans.
  findings: []
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: PubMed-verified. Supports a kidney alpha-intercalated-cell apical
      plasma membrane localization and PFK1-V-ATPase a-subunit interaction; peripheral
      to the core muscle enzyme function.
- id: PMID:21988832
  title: Toward an understanding of the protein interaction network of the human liver.
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: High-throughput liver interactome map; source of an uninformative
      bare protein binding IPI.
- id: PMID:24817713
  title: Crystallization and preliminary crystallographic analysis of human muscle
    phosphofructokinase, the main regulator of glycolysis.
  findings: []
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Full text available. Directly characterizes human muscle PFK as
      an M4 tetramer and describes the reaction and allosteric regulation; strongly
      supports complex, catalytic and glycolysis annotations.
- id: PMID:25416956
  title: A proteome-scale map of the human interactome network.
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: HuRI systematic binary interactome; source of uninformative protein
      binding / identical protein binding IPIs.
- id: PMID:25796446
  title: Aerobic glycolysis tunes YAP/TAZ transcriptional activity.
  findings: []
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: PubMed-verified. Establishes a moonlighting PFK1-TEAD/YAP-TAZ transcriptional
      role and nuclear localization in proliferating cells; supports the enzymatic
      activity but the transcriptional/nuclear annotations are context-specific and
      non-core.
- id: PMID:28514442
  title: Architecture of the human interactome defines protein communities and disease
    networks.
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: BioPlex 2.0 AP-MS interactome; source of an uninformative bare protein
      binding IPI.
- id: PMID:2960695
  title: Characterization of the enzymatic defect in late-onset muscle phosphofructokinase
    deficiency. New subtype of glycogen storage disease type VII.
  findings: []
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Characterizes muscle PFK deficiency (GSD VII); supports the muscle
      6-phosphofructokinase activity annotation.
- id: PMID:33961781
  title: Dual proteome-scale networks reveal cell-specific remodeling of the human
    interactome.
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: BioPlex 3.0 AP-MS interactome; source of an uninformative bare protein
      binding IPI.
- id: PMID:36115835
  title: Quantitative fragmentomics allow affinity mapping of interactomes.
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: High-throughput PDZ/affinity interactome mapping; source of uninformative
      bare protein binding IPIs (many PDZ-domain partners).
- id: PMID:6444532
  title: The molecular mechanism of the inherited phosphofructokinase deficiency associated
    with hemolysis and myopathy.
  findings: []
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Establishes that the M subunit is absent in Tarui disease and that
      muscle PFK activity is lost; supports the IMP/IDA activity, complex, and muscle
      homeostasis annotations.
- id: PMID:6444721
  title: 'Isozymes of human phosphofructokinase: identification and subunit structural
    characterization of a new system.'
  findings: []
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Defines the M/L subunit tetramer system (M4, M3L, M2L2, ML3, L4);
      supports complex assembly, identical/kinase binding, and 6-phosphofructokinase
      activity annotations.
- id: PMID:6451249
  title: 'Isozymes of human phosphofructokinase in blood cells and cultured cell lines:
    molecular and genetic evidence for a trigenic system.'
  findings: []
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: Abstract-only cached record supporting the trigenic (M/L/P) PFK
      system; Reactome-sourced EXP support for muscle 6-phosphofructokinase activity.
- id: PMID:7825568
  title: 'Functional expression of human mutant phosphofructokinase in yeast: genetic
    defects in French Canadian and Swiss patients with phosphofructokinase deficiency.'
  findings: []
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Reconstitutes human PFK-M activity in a PFK-null yeast system; the
      Gly209Asp GSD VII variant is completely inactive, directly supporting the 6-phosphofructokinase
      activity annotation.
- id: PMID:8780720
  title: Isozyme analysis of human polymorphonuclear leukocyte phosphofructokinase
    from insulin resistant individuals.
  findings: []
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: Measures M-type isozyme activity, F-6-P affinity and ATP inhibition;
      supports the IDA activity, ATP binding and fructose binding annotations.
- id: Reactome:R-HSA-70171
  title: Glycolysis
  findings: []
- id: Reactome:R-HSA-70467
  title: PFK tetramer phosphorylates Fru(6)P
  findings: []