GO:0006096 glycolysis: Metabolic Hub, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0006096 glycolysis is the biological process that breaks down carbohydrates into pyruvate while producing a small amount of ATP and reducing NAD(P) to NAD(P)H.
• Glycolysis is not only a bioenergetic pathway but also a signaling hub that influences cell proliferation, immune function, and disease progression.
• Key regulatory enzymes such as PFKFB3 and PKM2 control glycolytic flux and coordinate glycolysis with mitochondrial metabolism and oxidative phosphorylation.
• Tumor cells frequently rely on aerobic glycolysis to meet biosynthetic demands, making glycolytic enzymes attractive targets for cancer therapy.
• Glycolysis modulates immune cell function, including dendritic cell antitumor activity via STING signaling and CD8+ T cell activation.
• CRISPR-based knockout, point mutation, knock-in, and overexpression models enable precise dissection of glycolytic gene function in health and disease.
Description
Glycolysis (GO:0006096) is a central metabolic pathway that converts carbohydrates into pyruvate, generating ATP and reducing NAD(P) to NAD(P)H. This ancient pathway is conserved across all domains of life and serves as the backbone of cellular energy metabolism and biosynthesis. Beyond its classical role in energy production, glycolysis has emerged as a signaling hub that integrates nutrient availability with cell fate decisions, proliferation, and immune responses. Researchers study glycolysis to understand fundamental cell biology and to develop therapeutic strategies for cancer, sepsis, and immune disorders. The pathway is tightly regulated by enzymes such as PFKFB3 and PKM2, which respond to metabolic demands and oncogenic signals. In this article, we provide a comprehensive overview of glycolysis, its genetic components, regulatory mechanisms, disease relevance, and modern research methods including CRISPR-based models.
glycolysis At A Glance
| GO ID | GO:0006096 |
|---|---|
| GO term | glycolysis |
| Ontology | biological_process |
| Synonym | anaerobic glycolysis, Embden-Meyerhof-Parnas pathway, Embden-Meyerhof pathway, glycolytic process, modified Embden-Meyerhof pathway |
| Major function | Breakdown of carbohydrate into pyruvate with ATP production and NAD(P)H reduction |
| Key enzymes | HK2, PFKM, PFKFB3, PKM2, LDHA, GAPDH, ENO1, PGK1 |
| Pathway end products | Pyruvate, ATP, NADH; pyruvate can be converted to lactate, acetyl-CoA, or ethanol |
| Cellular location | Cytoplasm |
| Regulation | Allosteric regulation, transcriptional control, and signaling pathways such as mTOR and AMPK |
What Is GO:0006096?
Glycolysis is the chemical reactions and pathways that break down a carbohydrate into pyruvate, with the concomitant production of a small amount of ATP and the reduction of NAD(P) to NAD(P)H. The pathway begins with the metabolism of a carbohydrate to generate products that can enter the pathway and ends with the production of pyruvate. Pyruvate may be converted to acetyl-coenzyme A, ethanol, lactate, or other small molecules.
Why Is glycolysis Important in Cell Biology?
Glycolysis is essential for cellular energy production and biosynthesis, and its dysregulation is a hallmark of many diseases including cancer, sepsis, and immune dysfunction. The pathway provides rapidly dividing cells with ATP and biosynthetic precursors, making it a critical target for therapeutic intervention. Moreover, glycolytic intermediates feed into numerous biosynthetic pathways, and glycolytic enzymes can have non-metabolic signaling functions.
• Provides ATP and NADH for cellular energy metabolism under both aerobic and anaerobic conditions.
• Supports biosynthesis by generating precursors for nucleotides, amino acids, and lipids.
• Is reprogrammed in cancer cells (Warburg effect) to sustain proliferation and survival.
• Regulates immune cell function, including dendritic cell antitumor activity and CD8+ T cell activation.
• Contributes to sepsis pathogenesis through PFKFB3-driven glycolysis.
• Coordinates with mitochondrial fusion and oxidative phosphorylation via PKM2.
• Serves as a signaling hub that integrates nutrient status with cell fate decisions.
• Offers multiple druggable targets for cancer and inflammatory diseases.
• Is essential for normal development and tissue homeostasis.
• Can be studied with CRISPR models to dissect gene function in disease contexts.
What Happens During glycolysis?
Carbohydrate uptake and priming
In simple terms: The cell takes up glucose and traps it inside by adding a phosphate group.
Glycolysis begins with the metabolism of a carbohydrate to generate products that can enter the pathway. Glucose is phosphorylated by hexokinase (HK) to glucose-6-phosphate, which can then be isomerized to fructose-6-phosphate. This priming step consumes ATP and ensures that the sugar remains inside the cell. In cancer cells, hexokinase 2 (HK2) is often overexpressed to support high glycolytic flux.
Investment phase and cleavage
In simple terms: The cell spends another ATP to split the sugar into two three-carbon molecules.
Fructose-6-phosphate is phosphorylated by phosphofructokinase-1 (PFK-1) to fructose-1,6-bisphosphate, the committed step of glycolysis. PFK-1 is allosterically regulated by ATP, AMP, and fructose-2,6-bisphosphate, the latter produced by PFKFB3. Fructose-1,6-bisphosphate is then cleaved by aldolase into dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P). DHAP is converted to G3P by triosephosphate isomerase, resulting in two molecules of G3P per glucose.
Energy payoff phase
In simple terms: The cell extracts energy and electrons from the three-carbon molecules to make ATP and NADH.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) oxidizes G3P to 1,3-bisphosphoglycerate, reducing NAD+ to NADH. Phosphoglycerate kinase (PGK1) then transfers a phosphate to ADP, forming ATP. Phosphoglycerate mutase (PGAM) converts 3-phosphoglycerate to 2-phosphoglycerate, and enolase (ENO1) dehydrates it to phosphoenolpyruvate (PEP). Finally, pyruvate kinase (PKM2) transfers a phosphate from PEP to ADP, yielding pyruvate and ATP. The net yield per glucose is 2 ATP and 2 NADH.
Pyruvate fate and lactate production
In simple terms: Pyruvate can be turned into lactate, acetyl-CoA, or other molecules depending on the cell's needs.
Pyruvate may be converted to acetyl-coenzyme A, ethanol, lactate, or other small molecules. In aerobic conditions, pyruvate enters mitochondria for oxidative phosphorylation. In anaerobic conditions or in highly glycolytic cells, lactate dehydrogenase A (LDHA) reduces pyruvate to lactate, regenerating NAD+ to sustain glycolysis. This conversion is a hallmark of the Warburg effect in cancer cells.
Glycolysis as a signaling hub
In simple terms: Glycolytic enzymes also send signals that affect cell growth and immune responses.
Beyond ATP production, glycolysis acts as a signaling hub that influences cell proliferation, immune function, and disease progression. For example, glycolysis drives STING signaling to facilitate dendritic cell antitumor function. In CD8+ T cells, altered glycolysis levels affect activation and effector function. PKM2 coordinates glycolysis with mitochondrial fusion and oxidative phosphorylation, linking metabolic state to organelle dynamics.
Key Genes Involved in GO:0006096 glycolysis
The following genes encode enzymes and regulators that are central to glycolysis and are frequently studied in metabolic research.
| Gene | Major Role | Research Relevance |
|---|---|---|
| HK2 | Phosphorylates glucose to glucose-6-phosphate | Overexpressed in many cancers; target for glycolytic inhibition |
| GPI | Isomerizes glucose-6-phosphate to fructose-6-phosphate | Glycolytic enzyme; potential biomarker in metabolic disorders |
| PFKM | Phosphofructokinase-1, committed step of glycolysis | Allosteric regulation; mutations cause glycogen storage disease type VII |
| PFKFB3 | Produces fructose-2,6-bisphosphate to activate PFK-1 | Drives glycolysis in sepsis and cancer; therapeutic target |
| ALDOA | Cleaves fructose-1,6-bisphosphate into DHAP and G3P | Isoform-specific roles in cancer metabolism |
| TPI1 | Converts DHAP to G3P | Deficiency causes triosephosphate isomerase deficiency |
| GAPDH | Oxidizes G3P to 1,3-bisphosphoglycerate, reducing NAD+ | Moonlighting functions in apoptosis and transcription |
| PGK1 | Generates ATP from 1,3-bisphosphoglycerate | Regulated by oncogenic signals; involved in cancer progression |
| PGAM1 | Converts 3-phosphoglycerate to 2-phosphoglycerate | Target for cancer therapy; regulates biosynthesis |
| ENO1 | Dehydrates 2-phosphoglycerate to PEP | Cell surface receptor; role in cancer and autoimmunity |
| PKM2 | Final step of glycolysis, produces pyruvate and ATP | Coordinates glycolysis with mitochondrial dynamics |
| LDHA | Reduces pyruvate to lactate, regenerating NAD+ | Essential for aerobic glycolysis in cancer |
| SLC2A1 | Glucose transporter GLUT1 | Mediates glucose uptake; overexpressed in tumors |
| SLC2A3 | Glucose transporter GLUT3 | High-affinity transporter; important in neurons and cancer |
| PDK1 | Inhibits pyruvate dehydrogenase, shunting pyruvate to lactate | Regulates metabolic switch in cancer |
| HIF1A | Transcription factor inducing glycolytic genes | Master regulator of hypoxia response and Warburg effect |
| MYC | Transcription factor promoting glycolytic gene expression | Oncogene driving proliferation and glycolysis |
| TP53 | Tumor suppressor regulating glycolysis and oxidative phosphorylation | Loss of p53 enhances glycolysis in cancer |
How Is glycolysis Regulated?
Glycolysis is regulated at multiple levels, including allosteric control of key enzymes, transcriptional regulation by oncogenes and hypoxia-inducible factors, and signaling pathways such as mTOR and AMPK. PFKFB3 generates fructose-2,6-bisphosphate, which allosterically activates PFK-1 and is critical for glycolytic flux in sepsis and cancer. PKM2 is regulated by post-translational modifications and coordinates glycolysis with mitochondrial fusion and oxidative phosphorylation. In immune cells, glycolysis is modulated during activation and differentiation, affecting CD8+ T cell function and dendritic cell antitumor activity.
glycolysis and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PFKFB3 | Sepsis, cancer | Knockout or point-mutation models to assess glycolytic flux and inflammatory responses |
| PKM2 | Cancer, mitochondrial dynamics | Knock-in of phospho-mimetic or phospho-deficient mutants to study mitochondrial fusion |
| LDHA | Cancer, Warburg effect | Overexpression or knockout in cancer cell lines to evaluate lactate production and tumor growth |
| HK2 | Cancer, metabolic reprogramming | Knockout in cancer cells to test dependence on glycolysis |
| HIF1A | Hypoxia, cancer | Point mutation or knockout to dissect hypoxia-induced glycolytic gene expression |
Cancer
Cancer cells often exhibit increased aerobic glycolysis, known as the Warburg effect, to support rapid proliferation and biosynthesis. This metabolic reprogramming is driven by oncogenes such as MYC and HIF1A, and by loss of tumor suppressors like TP53. Glycolytic enzymes including HK2, PFKFB3, PKM2, and LDHA are frequently overexpressed in tumors and correlate with poor prognosis. Targeting glycolysis has emerged as a promising therapeutic strategy, with inhibitors of glycolytic enzymes under preclinical and clinical investigation.
Sepsis and inflammation
PFKFB3-driven glycolysis plays a critical role in sepsis pathogenesis, contributing to immune cell activation and cytokine production. Modulating glycolytic flux may offer therapeutic benefits in sepsis and other inflammatory conditions. Glycolysis also influences dendritic cell function and antitumor immunity through STING signaling.
Immune disorders
Altered glycolysis levels affect CD8+ T cell activation and function, with implications for antitumor immunity and autoimmune diseases. Glycolysis is essential for T cell effector function, and its dysregulation can lead to immune dysfunction. Understanding glycolytic regulation in immune cells may inform immunotherapeutic strategies.
Metabolic and mitochondrial disorders
PKM2 coordinates glycolysis with mitochondrial fusion and oxidative phosphorylation, linking glycolytic flux to mitochondrial dynamics. Defects in glycolytic enzymes can cause rare inherited metabolic disorders, such as triosephosphate isomerase deficiency and phosphofructokinase deficiency. Studying these pathways provides insight into mitochondrial diseases and metabolic syndromes.
From glycolysis-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate glycolytic flux? | CRISPR knockout of gene X in cell lines, followed by Seahorse or lactate assays |
| Does a specific phosphorylation site on PKM2 affect mitochondrial dynamics? | Point mutation (phospho-mimetic or phospho-deficient) knock-in |
| Does overexpression of PFKFB3 enhance sepsis severity? | Overexpression of PFKFB3 in immune cells or animal models |
| How does LDHA contribute to tumor growth? | Knockout or knockdown of LDHA in cancer xenografts |
| Does a glycolytic gene fusion drive oncogenesis? | Knock-in of fusion gene using CRISPR |
| What is the role of glycolysis in dendritic cell antitumor function? | Conditional knockout of glycolytic genes in dendritic cells |
How to Study the glycolysis Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Seahorse ECAR/OCR | Glycolytic and oxidative metabolism | Assessing metabolic reprogramming in cancer cells |
| 13C-glucose tracing | Flux through glycolytic intermediates | Quantifying pathway activity and branching |
| RNA-seq | Expression of glycolytic genes | Identifying transcriptional changes in disease models |
| Western blot | Protein levels and modifications | Validating knockout or overexpression efficiency |
| CRISPR knockout screens | Genes required for glycolysis | Discovering novel regulators and drug targets |
| Lactate assay | Lactate production | Measuring aerobic glycolysis (Warburg effect) |
| ATP luminescence | Intracellular ATP levels | Evaluating energy status after genetic perturbation |
| Fluorescent glucose uptake | Glucose transport activity | Imaging metabolic activity in live cells |
Metabolic flux analysis
Seahorse extracellular flux analysis measures extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) to assess glycolytic and oxidative metabolism in live cells. Isotope tracing with 13C-glucose followed by mass spectrometry quantifies glycolytic intermediates and pathway flux.
Gene expression and proteomics
RNA-seq and quantitative PCR measure expression of glycolytic genes such as HK2, PFKFB3, PKM2, and LDHA. Western blotting and mass spectrometry detect protein levels and post-translational modifications of glycolytic enzymes.
CRISPR screening
Genome-wide CRISPR knockout or activation screens identify genes that regulate glycolysis and cellular fitness under metabolic stress. Pooled screens with metabolic readouts can uncover novel regulators of glycolytic flux.
Imaging and functional assays
Fluorescent glucose analogs (e.g., 2-NBDG) and genetically encoded biosensors (e.g., HyPer, Peredox) enable real-time imaging of glucose uptake and redox state. Lactate production assays and ATP luminescence measure glycolytic output.
How CRISPR Can Be Used to Study GO:0006096 glycolysis
Knockout
CRISPR knockout of glycolytic genes such as HK2, PFKFB3, PKM2, or LDHA enables researchers to determine their essentiality for glycolysis, cell proliferation, and disease phenotypes. Knockout cell lines can be used in metabolic assays, xenograft models, and drug sensitivity screens.
Point Mutation
Point mutations can be introduced to study specific phosphorylation sites or catalytic residues in glycolytic enzymes. For example, phospho-mimetic or phospho-deficient mutants of PKM2 can reveal how post-translational modifications affect mitochondrial dynamics and oxidative phosphorylation.
Knock-in
Knock-in of tagged or fluorescently labeled glycolytic enzymes allows real-time tracking of protein localization and interactions. Knock-in of disease-associated mutations or fusion genes can model human metabolic disorders.
Overexpression
Overexpression of glycolytic genes such as PFKFB3 or LDHA can drive increased glycolytic flux and model the Warburg effect in cancer or sepsis. Overexpression models are useful for testing whether a gene is sufficient to induce metabolic reprogramming.
How EDITGENE Supports glycolysis Research
Researchers studying glycolysis-related genes often need to determine whether a candidate gene is causally involved in metabolic reprogramming, immune regulation, or disease progression. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell models for such functional studies.
Contact EDITGENE today to design your custom CRISPR model for glycolysis research.
Frequently Asked Questions About glycolysis
What is glycolysis (GO:0006096)?
Glycolysis is the biological process that breaks down carbohydrates into pyruvate, producing a small amount of ATP and reducing NAD(P) to NAD(P)H.
What genes are involved in glycolysis?
Key genes include HK2, PFKM, PFKFB3, ALDOA, GAPDH, PGK1, PGAM1, ENO1, PKM2, and LDHA, among others.
Why is glycolysis important in cancer?
Cancer cells often rely on aerobic glycolysis (the Warburg effect) to support rapid proliferation and biosynthesis, making glycolytic enzymes therapeutic targets.
How is glycolysis regulated?
Glycolysis is regulated by allosteric control, transcriptional programs involving HIF1A and MYC, and signaling pathways such as mTOR and AMPK.
What is the role of PFKFB3 in glycolysis?
PFKFB3 produces fructose-2,6-bisphosphate, which allosterically activates PFK-1 and drives glycolytic flux in sepsis and cancer.
How does PKM2 coordinate glycolysis with mitochondria?
PKM2 links glycolytic flux to mitochondrial fusion and oxidative phosphorylation, integrating metabolic state with organelle dynamics.
Can CRISPR be used to study glycolysis?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models enable precise dissection of glycolytic gene function in health and disease.
What methods measure glycolytic activity?
Seahorse ECAR, 13C-glucose tracing, lactate assays, and ATP luminescence are commonly used to measure glycolytic flux.
How does glycolysis affect immune cells?
Glycolysis drives STING signaling in dendritic cells and influences CD8+ T cell activation and function.
What diseases are linked to glycolysis dysfunction?
Cancer, sepsis, immune disorders, and rare metabolic enzyme deficiencies are associated with altered glycolysis.
Conclusion
Glycolysis (GO:0006096) is a fundamental metabolic pathway that sustains energy production and biosynthesis while also acting as a signaling hub in health and disease. Its dysregulation contributes to cancer, sepsis, and immune dysfunction, making it a prime target for therapeutic intervention. Advances in CRISPR-based models and metabolic profiling continue to uncover new layers of glycolytic regulation and its crosstalk with mitochondria and immune signaling. EDITGENE provides comprehensive services to support functional studies of glycolysis-related genes, from knockout and point mutation to library screening and bioinformatics.
References
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