GO:0000015 phosphopyruvate hydratase complex: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0000015 (phosphopyruvate hydratase complex) is a multimeric enzyme complex, usually a dimer or octamer, that catalyzes the conversion of 2-phospho-D-glycerate to phosphoenolpyruvate and water.
• The complex is commonly known as enolase, and its most studied subunit in humans is alpha-enolase (ENO1), a glycolytic enzyme with additional non-metabolic roles.
• ENO1 supports ATP production and lactate homeostasis in cancer cells, linking the complex to metabolic reprogramming.
• Beyond glycolysis, ENO1 can act as a transcriptional regulator by coupling to HDAC1 and influencing histone lactylation.
• Dysregulation of the complex is implicated in gastric cancer, intrahepatic cholangiocarcinoma, breast cancer, and inflammatory conditions such as rheumatoid arthritis.
• CRISPR-based knockout, knock-in, and overexpression models are essential to dissect the metabolic and non-metabolic functions of the phosphopyruvate hydratase complex.
Description
The phosphopyruvate hydratase complex (GO:0000015) is a cellular component defined as a multimeric enzyme complex, usually a dimer or an octamer, that catalyzes the conversion of 2-phospho-D-glycerate to phosphoenolpyruvate and water. This complex, widely known as enolase, occupies a central position in glycolysis, the pathway that generates ATP and supports biosynthetic precursors in rapidly proliferating cells. In humans, the most extensively studied subunit is alpha-enolase (ENO1), which forms the catalytic core of the complex and is overexpressed in many cancers. Researchers study GO:0000015 not only for its canonical metabolic role but also for its emerging non-metabolic functions, including transcriptional regulation and viral replication support. Understanding the composition, assembly, and regulation of this complex is therefore critical for both basic cell biology and translational oncology.
phosphopyruvate hydratase complex At A Glance
| GO ID | GO:0000015 |
|---|---|
| GO term | phosphopyruvate hydratase complex |
| Ontology | cellular_component |
| Synonym | enolase complex |
| Major function | Catalyzes conversion of 2-phospho-D-glycerate to phosphoenolpyruvate and water |
| Subunit composition | Usually a dimer or octamer |
| Common subunit in humans | Alpha-enolase (ENO1) |
| Cellular location | Cytoplasm |
| Related pathways | Glycolysis, gluconeogenesis, lactate homeostasis |
What Is GO:0000015?
According to the Gene Ontology, GO:0000015 (phosphopyruvate hydratase complex) is a multimeric enzyme complex, typically a dimer or an octamer, that catalyzes the dehydration of 2-phospho-D-glycerate to phosphoenolpyruvate and water. This reaction is a key step in glycolysis and gluconeogenesis. The complex is synonymous with enolase complex and is found in the cytoplasm of most organisms. Its activity is essential for energy metabolism and has been linked to additional moonlighting functions in gene regulation and disease.
Why Is phosphopyruvate hydratase complex Important in Cell Biology?
The phosphopyruvate hydratase complex is essential for glycolysis, the primary energy-producing pathway in many cells, and its activity directly influences ATP production and lactate levels. In cancer, elevated ENO1 expression supports the Warburg effect and promotes tumor growth, making the complex a potential therapeutic target. Moreover, ENO1 has non-glycolytic roles, such as regulating histone lactylation and gene transcription, which expand its importance beyond metabolism. Dysregulation of the complex has been observed in gastric cancer, intrahepatic cholangiocarcinoma, breast cancer, and rheumatoid arthritis, underscoring its broad clinical relevance.
• Central to glycolysis and ATP generation in proliferating cells.
• Supports lactate homeostasis and metabolic reprogramming in tumors.
• Exhibits non-metabolic functions in transcriptional regulation via HDAC1 interaction.
• Overexpressed in multiple cancers, including gastric and breast cancer.
• Contributes to ferroptosis resistance in intrahepatic cholangiocarcinoma.
• Implicated in inflammatory diseases such as rheumatoid arthritis.
• Plays a role in virus replication, highlighting non-metabolic functions.
• Serves as a target for CRISPR-based functional studies.
Core Biology of the phosphopyruvate hydratase complex
What Happens During phosphopyruvate hydratase complex?
In simple terms: The complex performs a key step in sugar breakdown to release energy.
The phosphopyruvate hydratase complex catalyzes the conversion of 2-phospho-D-glycerate to phosphoenolpyruvate and water, a dehydration reaction in glycolysis. This step is reversible and also functions in gluconeogenesis. The reaction generates phosphoenolpyruvate, a high-energy intermediate that drives subsequent ATP production. In cancer cells, this activity supports elevated glycolytic flux and lactate production.
Structure and Composition of phosphopyruvate hydratase complex
In simple terms: The complex is made of multiple identical or similar subunits that fit together like a molecular machine.
The complex is typically a dimer or octamer of enolase subunits. In humans, the most prevalent subunit is alpha-enolase (ENO1), a 47-kDa protein that can form dimers. Other isoforms include ENO2 (neuronal) and ENO3 (muscle), which can form homo- or heterodimers. The multimeric structure is essential for catalytic activity and stability. Post-translational modifications, such as lactylation, can affect subunit interactions and function.
Molecular Mechanism of phosphopyruvate hydratase complex
In simple terms: The complex uses a metal ion to pull water out of a molecule, creating a high-energy compound.
The catalytic mechanism involves a divalent metal ion, typically Mg2+, which stabilizes the substrate and facilitates the dehydration of 2-phospho-D-glycerate. The reaction proceeds through an enolate intermediate, resulting in phosphoenolpyruvate and water. The complex is regulated by metabolic cues, including lactate levels, which can modify lysine residues on ENO1 and alter its activity. Additionally, ENO1 can interact with HDAC1 to influence histone lactylation and gene transcription, revealing a moonlighting function.
Regulation of the phosphopyruvate hydratase complex
In simple terms: The complex is controlled by cellular signals that tell it when to speed up or slow down.
Regulation occurs at multiple levels: transcriptional control of ENO1 expression by oncogenic pathways, post-translational modifications such as lactylation and ubiquitination, and interaction with regulatory proteins like PSMD14 and EMC2. Lactylation of ENO1 can stabilize the protein and promote lactate production, contributing to ferroptosis resistance. Deubiquitination by EMC2 enhances ENO1 stability and breast cancer progression. These regulatory mechanisms fine-tune glycolytic flux and non-metabolic functions.
Key Genes Involved in GO:0000015 phosphopyruvate hydratase complex
The following genes and proteins are key components or regulators of the phosphopyruvate hydratase complex and its associated functions.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ENO1 | Alpha-enolase; catalytic subunit of the complex | Overexpressed in cancers; regulates glycolysis and lactate homeostasis |
| ENO2 | Neuronal enolase; alternative subunit | Potential role in neuronal metabolism and disease |
| ENO3 | Muscle enolase; alternative subunit | Associated with metabolic muscle disorders |
| HDAC1 | Histone deacetylase; interacts with ENO1 | Regulates histone lactylation and gene transcription |
| PSMD14 | Deubiquitinase; stabilizes ENO1 | Promotes lactate production and ferroptosis resistance |
| EMC2 | Deubiquitinase; stabilizes ENO1 | Enhances breast cancer progression and sensitivity to PDK1/AKT inhibition |
| PKM | Pyruvate kinase; downstream of enolase | Links glycolysis to lactate production |
| LDHA | Lactate dehydrogenase A; converts pyruvate to lactate | Regulates lactate homeostasis |
| HIF1A | Hypoxia-inducible factor 1-alpha | Upregulates glycolytic genes including ENO1 |
| MYC | Oncogenic transcription factor | Drives glycolytic gene expression |
| mTOR | Kinase; regulates metabolism | Controls glycolysis and enolase expression |
| AMPK | Energy sensor; regulates metabolism | Modulates glycolytic flux |
| GAPDH | Glycolytic enzyme; upstream of enolase | Provides substrate for enolase |
| PGAM1 | Phosphoglycerate mutase; upstream of enolase | Generates 2-phospho-D-glycerate |
| TPI1 | Triosephosphate isomerase; glycolytic enzyme | Supports glycolytic flux |
| ALDOA | Aldolase A; glycolytic enzyme | Contributes to glycolysis |
| PFKM | Phosphofructokinase; rate-limiting glycolytic enzyme | Regulates glycolytic rate |
| SLC2A1 | Glucose transporter GLUT1 | Facilitates glucose uptake for glycolysis |
How Is phosphopyruvate hydratase complex Regulated?
The phosphopyruvate hydratase complex is regulated at multiple levels. Transcriptional regulation of ENO1 is influenced by oncogenic pathways such as HIF1A and MYC, which upregulate glycolytic genes under hypoxia or proliferative signals. Post-translational modifications, including lactylation and ubiquitination, directly affect ENO1 stability and activity; for example, lactylation by PSMD14 promotes lactate production and ferroptosis resistance, while deubiquitination by EMC2 stabilizes ENO1 and enhances breast cancer progression. Additionally, ENO1 interacts with HDAC1 to modulate histone lactylation and gene transcription, linking metabolism to epigenetic regulation. These regulatory mechanisms ensure that the complex responds to cellular energy demands and stress conditions.
phosphopyruvate hydratase complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ENO1 | Gastric cancer; ATP pool and lactate homeostasis | ENO1 knockout gastric cancer cell lines |
| ENO1 | Intrahepatic cholangiocarcinoma; ferroptosis resistance | ENO1 point-mutation or overexpression models |
| ENO1 | Breast cancer; progression and PDK1/AKT sensitivity | ENO1 knockout or knock-in breast cancer cells |
| ENO1 | Rheumatoid arthritis; inflammation | ENO1 overexpression in immune cells |
| ENO1 | Virus replication | ENO1 knockout in virus-infected cells |
Cancer metabolism and ENO1
ENO1 is overexpressed in many cancers and supports the Warburg effect by enhancing glycolysis and lactate production. In gastric cancer, alpha-enolase influences the cytoplasmic ATP pool and lactate homeostasis, promoting tumor growth. In intrahepatic cholangiocarcinoma, L-lactate-driven lactylation of PSMD14 stabilizes ENO1, leading to increased lactate production and ferroptosis resistance. EMC2-mediated deubiquitination of ENO1 promotes breast cancer progression and alters sensitivity to PDK1/AKT inhibition. These findings highlight the complex as a potential therapeutic target.
Non-metabolic roles in gene regulation
Beyond glycolysis, ENO1 can localize to the nucleus and interact with HDAC1 to regulate histone lactylation and gene transcription. This moonlighting function links the phosphopyruvate hydratase complex to epigenetic control and may contribute to cancer cell plasticity. Targeting this interaction could provide new therapeutic avenues.
Inflammatory and metabolic disorders
Glycolytic enzymes, including enolase, are implicated in rheumatoid arthritis, where altered metabolism of immune cells contributes to inflammation. Metabolic muscle disorders can also involve enolase deficiencies, although specific mutations in ENO3 are rare. These conditions underscore the broad physiological importance of the complex.
Viral replication
Alpha-enolase has been shown to play a non-metabolic role in virus replication, potentially by interacting with viral proteins or modulating host cell metabolism. This expands the relevance of the complex beyond cancer and metabolism.
From phosphopyruvate hydratase complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does ENO1 loss affect glycolysis and ATP production? | ENO1 knockout cell lines |
| Does a specific ENO1 mutation alter lactate homeostasis? | ENO1 point-mutation knock-in cells |
| Does ENO1 lactylation regulate ferroptosis? | ENO1 knock-in with lactylation-site mutations |
| Does ENO1 interact with HDAC1 to regulate transcription? | Tagged ENO1 knock-in for co-IP |
| Does ENO1 overexpression promote tumor growth? | ENO1 overexpression cell lines and xenografts |
| Can ENO1 be targeted to enhance therapy? | ENO1 knockout combined with PDK1/AKT inhibitors |
How to Study the phosphopyruvate hydratase complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout screen | Gene essentiality and synthetic lethality | Identify regulators of enolase complex |
| Co-immunoprecipitation | Protein-protein interactions | Detect ENO1-HDAC1 interaction |
| Mass spectrometry | Post-translational modifications | Identify lactylation sites on ENO1 |
| Seahorse assay | Glycolytic rate and oxygen consumption | Measure metabolic flux after ENO1 manipulation |
| Lactate assay | Lactate production | Assess lactate homeostasis |
| Western blot | Protein expression and modification | Validate ENO1 levels and lactylation |
| Immunofluorescence | Subcellular localization | Study nuclear ENO1 |
| RNA-seq | Transcriptional changes | Analyze gene expression after ENO1 knockout |
CRISPR knockout screens
Genome-wide CRISPR knockout screens can identify genes that are essential for the function of the phosphopyruvate hydratase complex or that synthetic-lethal with ENO1 loss. Such screens have been used to uncover metabolic vulnerabilities in cancer cells.
Proteomics and interactomics
Affinity purification coupled with mass spectrometry can identify interacting partners of the complex, such as HDAC1 and PSMD14. These methods reveal the composition and post-translational modifications of the complex.
Metabolic assays
Seahorse extracellular flux analysis, lactate measurements, and ATP assays quantify the metabolic impact of manipulating the complex. These are essential for linking genotype to metabolic phenotype.
Imaging and localization
Fluorescence microscopy with tagged ENO1 can reveal subcellular localization, including nuclear translocation, and its interaction with chromatin. This helps study non-metabolic functions.
How CRISPR Can Be Used to Study GO:0000015 phosphopyruvate hydratase complex
Knockout
CRISPR-Cas9 knockout of ENO1 or other subunits can abolish complex activity, leading to impaired glycolysis and reduced ATP production. Knockout models are used to study the metabolic and non-metabolic roles of the complex, including effects on lactate homeostasis and ferroptosis.
Point Mutation
Introducing specific point mutations in ENO1, such as at lactylation sites, can dissect the contribution of post-translational modifications to complex function. Point-mutation models help distinguish catalytic activity from regulatory interactions.
Knock-in
Knock-in of tagged ENO1 (e.g., FLAG or GFP) allows for affinity purification and imaging of the complex in live cells. This approach is valuable for studying interacting partners and subcellular localization.
Overexpression
Overexpression of ENO1 can mimic the elevated levels seen in cancers and is used to study its oncogenic potential and effects on lactate production and therapy resistance. Overexpression models are also useful for testing inhibitors.
How EDITGENE Supports phosphopyruvate hydratase complex Research
Researchers studying phosphopyruvate hydratase complex-related genes often need to determine whether a candidate gene is causally involved in metabolic reprogramming, tumor growth, or non-metabolic functions. EDITGENE provides a comprehensive suite of CRISPR services to enable such investigations, from knockout to precise point mutations and library screening.
Contact EDITGENE today to design your custom CRISPR model for phosphopyruvate hydratase complex research.
Frequently Asked Questions About phosphopyruvate hydratase complex
What is the phosphopyruvate hydratase complex?
It is a multimeric enzyme complex, usually a dimer or octamer, that catalyzes the conversion of 2-phospho-D-glycerate to phosphoenolpyruvate and water, commonly known as enolase.
What genes are involved in the phosphopyruvate hydratase complex?
The main human genes are ENO1 (alpha-enolase), ENO2 (neuronal enolase), and ENO3 (muscle enolase), with ENO1 being the most studied.
What is the function of GO:0000015?
GO:0000015 is a cellular component term describing the enolase complex that performs a key step in glycolysis and gluconeogenesis.
How is the phosphopyruvate hydratase complex regulated?
It is regulated by transcriptional control, post-translational modifications such as lactylation and ubiquitination, and interactions with proteins like HDAC1 and PSMD14.
What diseases are associated with the phosphopyruvate hydratase complex?
It is implicated in cancers such as gastric cancer, intrahepatic cholangiocarcinoma, and breast cancer, as well as rheumatoid arthritis and viral infections.
What is alpha-enolase (ENO1)?
ENO1 is the alpha isoform of enolase and a major subunit of the phosphopyruvate hydratase complex; it is overexpressed in many cancers and has non-metabolic roles.
How can CRISPR be used to study the phosphopyruvate hydratase complex?
CRISPR knockout, point mutation, knock-in, and overexpression models allow researchers to dissect the metabolic and non-metabolic functions of the complex.
What methods are used to study the phosphopyruvate hydratase complex?
Common methods include CRISPR screens, co-immunoprecipitation, mass spectrometry, Seahorse assays, lactate measurements, and imaging.
Is the phosphopyruvate hydratase complex a potential drug target?
Yes, its role in cancer metabolism and lactate production makes it a candidate for therapeutic targeting, though further research is needed.
What is the difference between ENO1, ENO2, and ENO3?
They are isoforms of enolase with tissue-specific expression: ENO1 is ubiquitous, ENO2 is neuronal, and ENO3 is muscle-specific; they can form different complexes.
Conclusion
The phosphopyruvate hydratase complex (GO:0000015) is a fundamental glycolytic machine with expanding roles in cancer, metabolism, and gene regulation. Its main subunit, ENO1, is a multifunctional protein that supports tumor growth and lactate homeostasis, and its dysregulation is linked to multiple diseases. Understanding the complex's structure, regulation, and non-metabolic functions requires advanced experimental models, and CRISPR-based approaches are indispensable for this research. EDITGENE offers comprehensive services to facilitate such studies, from knockout to library screening, empowering researchers to uncover new therapeutic targets.
References
- 1. Shu X et al.. 2025. Alpha-enolase influences ATP pool of cytoplasm and lactate homeostasis by regulating glycolysis in gastric cancer.. Signal Transduct Target Ther 10(1):356 PMID: 41168198
- 2. Cai D et al.. 2026. L-lactate-driven PSMD14 lactylation and stabilization promote lactate production and ferroptosis resistance via ENO1 in intrahepatic cholangiocarcinoma.. Cancer Lett 646:218394 PMID: 41786282
- 4. Zhai G et al.. 2026. ENO1 couples HDAC1 to regulate histone lactylation and gene transcription.. Proc Natl Acad Sci U S A 123(25):e2535245123 PMID: 42308038
- 5. Xiao S et al.. 2025. EMC2 promotes breast cancer progression and enhances sensitivity to PDK1/AKT inhibition by deubiquitinating ENO1.. Int J Biol Sci 21(6):2629-2646 PMID: 40303285
- 6. Chang X et al.. 2011. Glycolysis and rheumatoid arthritis.. Int J Rheum Dis 14(3):217-22 PMID: 21816017
- 7. Vadlamani S et al.. 2023. Non-metabolic role of alpha-enolase in virus replication.. Mol Biol Rep 50(2):1677-1686 PMID: 36402937
- 8. Scarlato G et al.. 2002. Metabolic and drug-induced muscle disorders.. Curr Opin Neurol 15(5):533-8 PMID: 12351996
