Pfk1 (SPBC16H5.02) is the ATP-dependent 6-phosphofructokinase of the fission yeast Schizosaccharomyces pombe, a two-domain PFKA-family enzyme of 942 residues encoded by a single gene. It catalyses the phosphorylation of fructose 6-phosphate by ATP to fructose 1,6-bisphosphate in the cytosol, the first committed step of glycolysis. Unlike the hetero-octameric (alpha4beta4) phosphofructokinase of Saccharomyces cerevisiae, the S. pombe enzyme is a homo-octamer of ~100 kDa subunits (~800 kDa). Kinetically it shows weaker cooperativity toward fructose 6-phosphate and weaker ATP inhibition than the budding-yeast enzyme; fructose 2,6-bisphosphate and AMP relieve ATP inhibition and raise its affinity for fructose 6-phosphate. Expression of S. pombe pfk1 restores glucose growth to a S. cerevisiae pfk1 pfk2 double mutant.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0003872 6-phosphofructokinase activity | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA (node PTN000344216) for 6-phosphofructokinase activity; pfk1 itself is among the experimental donors (Reuter et al. purified enzyme kinetics), so the inherited ATP-dependent PFK activity is directly grounded on this protein. Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt Reaction=beta-D-fructose 6-phosphate + ATP = beta-D-fructose 1,6- PMID:11015725 Fructose 2,6-bisphosphate (in micromolar range) and AMP (in millimolar range) were found to overcome ATP inhibition and to increase the affinity to fructose 6-phosphate. |
| GO:0003872 6-phosphofructokinase activity | IDA PMID:11015725 Purification, molecular and kinetic characterization of phos... | ACCEPT | Summary: Reuter et al. purified S. pombe Pfk1 to homogeneity and characterised its kinetics toward fructose 6-phosphate and ATP, including activation by fructose 2,6-bisphosphate and AMP; direct evidence for the core catalytic activity. Supporting Evidence: PMID:11015725 Fructose 2,6-bisphosphate (in micromolar range) and AMP (in millimolar range) were found to overcome ATP inhibition and to increase the affinity to fructose 6-phosphate. PMID:11015725 The Pfk-1 coding sequence of S. pombe was transformed into a Pfk-1 double deletion mutants of Saccharomyces cerevisiae resulting in glucose-positive cells with enzyme activity in the crude cell extract. |
| GO:0003872 6-phosphofructokinase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Combined automated mapping (EC 2.7.1.11 / RHEA:16109) to 6-phosphofructokinase activity; correct for this ATP-dependent PFKA-family enzyme and consistent with the experimental data. Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt Reaction=beta-D-fructose 6-phosphate + ATP = beta-D-fructose 1,6- |
| GO:0005524 ATP binding | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: InterPro PFK-domain mapping to ATP binding. ATP is the phosphoryl-donor substrate and an allosteric inhibitor of Pfk1; true but a component of the catalytic activity rather than a separate function. Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt Reaction=beta-D-fructose 6-phosphate + ATP = beta-D-fructose 1,6- file:SCHPO/pfk1/pfk1-uniprot.txt ACTIVITY REGULATION: Allosterically activated by ADP, AMP, or fructose |
| GO:0005737 cytoplasm | HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ... | ACCEPT | Summary: Genome-wide YFP-tagged ORFeome localisation (Matsuyama et al. 2006) placed Pfk1 in the cytoplasm; consistent with a soluble glycolytic enzyme. Supporting Evidence: PMID:16823372 we determined the localization of 4,431 proteins |
| GO:0005737 cytoplasm | IEA GO_REF:0000120 | ACCEPT | Summary: Combined automated (HAMAP MF_03184 subcellular location) mapping to cytoplasm; correct, though cytosol is the more specific location supported by the HDA data. Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_03184}. |
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: IBA mitochondrion from PANTHER node PTN001008801, whose experimental donors are the S. cerevisiae Pfk1/Pfk2 subunits (proteomic association of glycolytic enzymes with budding-yeast mitochondria). No S. pombe data show a mitochondrial pool of Pfk1; the ORFeome screen places it in the cytosol. Retained as a non-core, inherited peripheral association, consistent with the S. cerevisiae PFK1 review. Reason: Peripheral mitochondrial association transferred from budding yeast; not where the core PFK activity operates, and not observed for S. pombe Pfk1. Supporting Evidence: PMID:16823372 we determined the localization of 4,431 proteins |
| GO:0005829 cytosol | HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ... | ACCEPT | Summary: ORFeome YFP localisation places Pfk1 in the cytosol, the compartment in which glycolysis runs and the location used in the PomBase glycolysis GO-CAM. Supporting Evidence: PMID:16823372 we determined the localization of 4,431 proteins |
| GO:0005945 6-phosphofructokinase complex | IBA GO_REF:0000033 | ACCEPT | Summary: IBA 6-phosphofructokinase complex. S. pombe Pfk1 forms a homo-octamer (unlike the S. cerevisiae alpha4beta4 hetero-octamer), which falls within the GO definition of the complex (homooctameric forms included). Supporting Evidence: PMID:11015725 showed that the enzyme is composed of subunits of identical size of 100+/-5 kDa, forming an octameric structure. PMID:17643314 Schizosaccharomyces pombe Pfk1 is a homo-octameric enzyme of 800 kDa molecular weight, distinct from its yeast counterparts which are mostly hetero-octameric enzymes composed of two different subunits. |
| GO:0005945 6-phosphofructokinase complex | IDA PMID:11015725 Purification, molecular and kinetic characterization of phos... | ACCEPT | Summary: Reuter et al. showed by sedimentation equilibrium, SDS-PAGE and MALDI-TOF that native Pfk1 is a ~790 kDa octamer of identical ~100 kDa subunits; direct evidence for a homo-octameric PFK complex. Supporting Evidence: PMID:11015725 showed that the enzyme is composed of subunits of identical size of 100+/-5 kDa, forming an octameric structure. |
| GO:0005945 6-phosphofructokinase complex | IDA PMID:17643314 Structures of S. pombe phosphofructokinase in the F6P-bound ... | ACCEPT | Summary: Benjamin et al. 3D electron-microscopy reconstructions of purified Pfk1 in the F6P-bound and ATP-bound states confirm the homo-octameric quaternary structure. Supporting Evidence: PMID:17643314 Schizosaccharomyces pombe Pfk1 is a homo-octameric enzyme of 800 kDa molecular weight, distinct from its yeast counterparts which are mostly hetero-octameric enzymes composed of two different subunits. PMID:17643314 Electron microscopy studies were carried out to reveal the quaternary structure of the homo-octameric Pfk1 from S. pombe in the F6P-bound and in the ATP-bound state. |
| GO:0005945 6-phosphofructokinase complex | IEA GO_REF:0000117 | ACCEPT | Summary: ARBA/UniRule-based mapping to 6-phosphofructokinase complex; correct for this octameric enzyme. Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt SUBUNIT: Homooctamer. |
| GO:0005945 6-phosphofructokinase complex | IPI PMID:17643314 Structures of S. pombe phosphofructokinase in the F6P-bound ... | ACCEPT | Summary: ComplexPortal-sourced IPI for the homo-octameric Pfk1 complex based on the EM structure paper; correct. Supporting Evidence: PMID:17643314 Schizosaccharomyces pombe Pfk1 is a homo-octameric enzyme of 800 kDa molecular weight, distinct from its yeast counterparts which are mostly hetero-octameric enzymes composed of two different subunits. |
| GO:0006002 fructose 6-phosphate metabolic process | IBA GO_REF:0000033 | ACCEPT | Summary: IBA fructose 6-phosphate metabolic process; Pfk1 consumes fructose 6-phosphate. Correct but a broad metabolite-centred process; the pathway-level process is glycolysis. Kept as accepted for consistency with the S. cerevisiae PFK1 review. Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt Catalyzes the phosphorylation of D-fructose 6-phosphate to |
| GO:0006002 fructose 6-phosphate metabolic process | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro (PFK family) mapping to fructose 6-phosphate metabolic process; correct description of the substrate-level process. Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt Catalyzes the phosphorylation of D-fructose 6-phosphate to |
| GO:0006096 glycolysis | IDA PMID:11015725 Purification, molecular and kinetic characterization of phos... | ACCEPT | Summary: Reuter et al.: purified Pfk1 catalyses the committed glycolytic step and the S. pombe gene restores glucose growth to a S. cerevisiae pfk1 pfk2 double deletion, supporting participation in glycolysis. Supporting Evidence: PMID:11015725 The Pfk-1 coding sequence of S. pombe was transformed into a Pfk-1 double deletion mutants of Saccharomyces cerevisiae resulting in glucose-positive cells with enzyme activity in the crude cell extract. file:SCHPO/pfk1/pfk1-uniprot.txt Catalyzes the phosphorylation of D-fructose 6-phosphate to |
| GO:0006096 glycolysis | IEA GO_REF:0000120 | ACCEPT | Summary: UniPathway/combined automated mapping to glycolysis; correct, Pfk1 catalyses step 3 of glycolysis. Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt PATHWAY: Carbohydrate degradation; glycolysis; D-glyceraldehyde 3- |
| GO:0030388 fructose 1,6-bisphosphate metabolic process | IBA GO_REF:0000033 | ACCEPT | Summary: IBA fructose 1,6-bisphosphate metabolic process; Pfk1 produces fructose 1,6-bisphosphate. Correct but broad; consistent with the S. cerevisiae PFK1 review. Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt Reaction=beta-D-fructose 6-phosphate + ATP = beta-D-fructose 1,6- |
| GO:0032473 cytoplasmic side of mitochondrial outer membrane | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: PomBase ISS to S. cerevisiae Pfk2 (P16862), which UniProt records as a peripheral protein on the cytoplasmic side of the mitochondrial outer membrane from the Brandina et al. mitochondrial-association study. Plausible by orthology but untested in S. pombe and peripheral to the cytosolic core function. Reason: Curator-made orthology transfer of a peripheral budding-yeast localisation; not contradicted, but not the site of core activity. Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt Catalyzes the phosphorylation of D-fructose 6-phosphate to |
| GO:0061615 obsolete glycolytic process through fructose-6-phosphate | IEA GO_REF:0000117 | MODIFY | Summary: ARBA mapping to 'glycolytic process through fructose-6-phosphate', a term obsoleted by GO (2026-09-01) and replaced by glycolysis (GO:0006096). The biology is correct; the term should be updated. Reason: Obsolete term; GO replaced_by GO:0006096. Proposed replacements: glycolysis Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt Catalyzes the phosphorylation of D-fructose 6-phosphate to |
| GO:0061621 obsolete canonical glycolysis | EXP PMID:11015725 Purification, molecular and kinetic characterization of phos... | MODIFY | Summary: PomBase EXP annotation from Reuter et al. to 'canonical glycolysis', which GO obsoleted (2026-09-01) because it represented a GO-CAM model; replaced_by glycolysis (GO:0006096). The experimental basis (purified enzyme, complementation of S. cerevisiae pfk mutants) is sound. Reason: Obsolete term; GO replaced_by GO:0006096. Proposed replacements: glycolysis Supporting Evidence: PMID:11015725 The Pfk-1 coding sequence of S. pombe was transformed into a Pfk-1 double deletion mutants of Saccharomyces cerevisiae resulting in glucose-positive cells with enzyme activity in the crude cell extract. |
| GO:0061621 obsolete canonical glycolysis | IBA GO_REF:0000033 | MODIFY | Summary: IBA to obsolete 'canonical glycolysis' (replaced_by GO:0006096 glycolysis); content correct, term needs updating. Reason: Obsolete term; GO replaced_by GO:0006096. Propagation Review Root cause: SOURCE STALE OR MISSING Proposed replacements: glycolysis Supporting Evidence: file:SCHPO/pfk1/pfk1-uniprot.txt Catalyzes the phosphorylation of D-fructose 6-phosphate to |
| GO:0070095 fructose-6-phosphate binding | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: IBA fructose-6-phosphate binding; substrate binding inherent to PFK catalysis. Correct but subsumed by the catalytic activity; non-core, as in the S. cerevisiae PFK1 review. Supporting Evidence: PMID:17643314 Electron microscopy studies were carried out to reveal the quaternary structure of the homo-octameric Pfk1 from S. pombe in the F6P-bound and in the ATP-bound state. |
| GO:0070095 fructose-6-phosphate binding | IDA PMID:17643314 Structures of S. pombe phosphofructokinase in the F6P-bound ... | KEEP AS NON CORE | Summary: Benjamin et al. reconstructed Pfk1 in the F6P-bound (R-state) conformation; F6P binding is a substrate-binding aspect of the PFK activity rather than an independent function. Supporting Evidence: PMID:17643314 Electron microscopy studies were carried out to reveal the quaternary structure of the homo-octameric Pfk1 from S. pombe in the F6P-bound and in the ATP-bound state. |
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Download this section (compressed HTML)Q: Does the distinct N-terminal region of S. pombe Pfk1 determine its homo-octameric assembly, and does it carry the allosteric functions that are split between the alpha and beta subunits in S. cerevisiae?
Experiment: Map allosteric effector sites in homo-octameric S. pombe Pfk1 by cryo-EM with AMP, fructose 2,6-bisphosphate and inhibitory ATP bound, and compare with the S. cerevisiae Pfk1/Pfk2 hetero-octamer.
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