GO:0004396 hexokinase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004396 hexokinase activity is a molecular function defined as the catalysis of ATP + D-hexose = ADP + D-hexose 6-phosphate.
• Hexokinase enzymes, particularly HK1 and HK2, phosphorylate glucose to glucose-6-phosphate, the first committed step of glycolysis.
• HK2 is dynamically regulated in immune cells and cancer, linking glycolysis to mitochondrial metabolism and cell death.
• Hexokinase activity is redox-regulated and can influence sugar-nucleotide formation and biosynthetic pathways.
• Dysregulated hexokinase activity contributes to cancer, inflammatory bowel disease, and metabolic dysfunction-associated steatotic liver disease.
• CRISPR knockout, knock-in, and overexpression models are essential to dissect isoform-specific hexokinase functions in disease.
Description
Hexokinase activity (GO:0004396) is a fundamental molecular function that catalyzes the ATP-dependent phosphorylation of D-hexose sugars to their 6-phosphate derivatives. This reaction, ATP + D-hexose = ADP + D-hexose 6-phosphate, represents the first committed step of glycolysis and is critical for glucose sensing and metabolic flux. In mammals, multiple hexokinase isoforms (HK1, HK2, HK3, HK4/glucokinase) exhibit distinct tissue distributions and regulatory properties, enabling specialized metabolic roles. The importance of hexokinase activity extends beyond energy production; it interfaces with mitochondrial metabolism, cell death pathways, and biosynthetic processes. Recent studies have highlighted hexokinase 2 (HK2) as a key regulator of immune cell function, inflammation, and tumor progression, making it a focal point for therapeutic intervention. Understanding the molecular mechanisms, regulation, and disease relevance of hexokinase activity is therefore essential for researchers in metabolism, immunology, and oncology.
hexokinase activity At A Glance
| GO ID | GO:0004396 |
|---|---|
| GO term | hexokinase activity |
| Ontology | molecular_function |
| Synonym | ATP-dependent hexokinase activity; ATP:D-hexose 6-phosphotransferase activity; glucose ATP phosphotransferase activity; hexokinase D; hexokinase (phosphorylating); hexokinase type I activity; hexokinase type II activity; hexokinase type III activity; hexokinase type IV; hexokinase type IV (glucokinase) activity; hexokinase type IV glucokinase activity |
| Major function | Catalysis of ATP + D-hexose = ADP + D-hexose 6-phosphate |
| EC number | 2.7.1.1 |
| Substrates | ATP and D-hexose (e.g., D-glucose, D-fructose, D-mannose) |
| Products | ADP and D-hexose 6-phosphate |
| Cofactors | Magnesium ions (Mg2+) required for ATP binding |
| Localization | Cytosol and outer mitochondrial membrane (for HK1 and HK2) |
What Is GO:0004396?
Hexokinase activity (GO:0004396) is defined by the Gene Ontology as the catalysis of the reaction: ATP + D-hexose = ADP + D-hexose 6-phosphate. This activity transfers a phosphate group from ATP to a hexose sugar, producing a hexose 6-phosphate and ADP. It is a phosphotransferase activity that requires ATP as the phosphate donor and acts on D-hexose substrates, with glucose being the most common in vivo substrate. The reaction is irreversible under physiological conditions and serves as the rate-limiting step of glycolysis.
Why Is hexokinase activity Important in Cell Biology?
Hexokinase activity is essential for glucose metabolism, as it traps glucose inside the cell and initiates glycolysis, the primary pathway for energy production and biosynthetic precursor generation. Beyond its housekeeping role, hexokinase activity is a critical node in metabolic reprogramming observed in cancer, immune activation, and inflammation. Isoform-specific functions, particularly HK2, have been linked to mitochondrial integrity, cell death regulation, and epigenetic modifications via histone lactylation. Consequently, hexokinase activity is a promising target for therapeutic strategies in oncology, inflammatory diseases, and metabolic disorders.
• Hexokinase activity catalyzes the first committed step of glycolysis, controlling glucose entry into metabolism.
• HK2 is highly expressed in many cancers and supports tumor growth by sustaining glycolytic flux.
• Hexokinase activity modulates mitochondrial metabolism and cell death in colitis and inflammation.
• HK2 senses fructose in tumor-associated macrophages to promote colorectal cancer.
• Hexokinase activity influences histone lactylation and inflammatory burden in MASLD.
• Redox regulation of hexokinases links oxidative stress to metabolic adaptation.
• Hexokinase activity affects sugar-nucleotide formation and cell wall biosynthesis in plants.
• Altered hexokinase expression correlates with inflammation severity in IBD patients.
• Hexokinase activity is critical for microglial function by gating glycolytic flux and mitochondrial activity.
• Isoform-specific hexokinase functions provide opportunities for targeted therapeutic intervention.
What Happens During hexokinase activity?
Substrate binding and conformational change
In simple terms: Hexokinase grabs ATP and a sugar molecule, changes shape, and gets ready to transfer a phosphate.
Hexokinase binds ATP and D-hexose in a sequential ordered mechanism. The enzyme undergoes a conformational change upon glucose binding, which brings the substrates into proximity and excludes water from the active site, preventing ATP hydrolysis. This induced-fit mechanism ensures efficient phosphoryl transfer.
Phosphoryl transfer
In simple terms: The enzyme moves a phosphate from ATP onto the sugar, making glucose-6-phosphate.
The catalytic mechanism involves the transfer of the gamma-phosphate of ATP to the C6 hydroxyl group of D-hexose, producing D-hexose 6-phosphate and ADP. This reaction is irreversible and requires magnesium ions as cofactors to neutralize the negative charges of ATP. The product glucose-6-phosphate is a key metabolic intermediate.
Product release and metabolic channeling
In simple terms: The newly made glucose-6-phosphate is released and enters various metabolic pathways.
After catalysis, glucose-6-phosphate is released from the active site. It can then enter glycolysis, the pentose phosphate pathway, or glycogen synthesis. In some organisms, hexokinase activity is coupled to sugar-nucleotide formation, influencing cell wall biosynthesis. In mammalian cells, mitochondrial-associated hexokinases (HK1, HK2) preferentially channel glucose-6-phosphate into glycolysis.
Isoform-specific variations
In simple terms: Different hexokinase types have slightly different jobs and are found in different tissues.
Mammalian hexokinases include HK1 (ubiquitous), HK2 (insulin-sensitive tissues and cancers), HK3 (neutrophils), and HK4/glucokinase (liver and pancreas). These isoforms differ in their kinetic properties, subcellular localization, and regulation. For example, HK2 binds to the outer mitochondrial membrane via VDAC, which enhances its activity and links glycolysis to mitochondrial metabolism.
Key Genes Involved in GO:0004396 hexokinase activity
The following genes encode proteins with hexokinase activity or directly regulate it, as supported by published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| HK1 | Hexokinase 1, ubiquitous isoform, binds mitochondria | Maintains basal glycolysis; knockout models show metabolic defects |
| HK2 | Hexokinase 2, insulin-sensitive, highly expressed in cancer | Key regulator of tumor metabolism, immune cell function, and inflammation |
| HK3 | Hexokinase 3, expressed in neutrophils and some tissues | Less studied; potential role in immune cell metabolism |
| GCK | Glucokinase (hexokinase 4), liver and pancreatic beta cells | Glucose sensing and insulin secretion; mutations cause MODY2 |
| VDAC1 | Voltage-dependent anion channel, binds HK2 at mitochondria | Regulates HK2 mitochondrial association and apoptosis |
| PFKM | Phosphofructokinase, muscle isoform | Downstream glycolytic enzyme; coordinated with hexokinase activity |
| GYS1 | Glycogen synthase, muscle isoform | Utilizes glucose-6-phosphate for glycogen synthesis |
| TIGAR | TP53-induced glycolysis and apoptosis regulator | Modulates glycolytic flux and hexokinase activity |
| SLC2A1 | GLUT1 glucose transporter | Upstream of hexokinase; regulates glucose uptake |
| SLC2A4 | GLUT4 glucose transporter | Insulin-responsive glucose uptake; linked to HK2 in muscle |
| AKT1 | Protein kinase B | Phosphorylates HK2, promoting mitochondrial binding |
| MTOR | Mechanistic target of rapamycin | Regulates glycolysis and hexokinase expression |
| HIF1A | Hypoxia-inducible factor 1-alpha | Induces HK2 expression under hypoxia |
| MYC | MYC proto-oncogene | Drives HK2 transcription in cancer |
| TP53 | Tumor protein p53 | Regulates glycolysis and hexokinase activity via TIGAR |
| LDHA | Lactate dehydrogenase A | Converts pyruvate to lactate; linked to hexokinase flux |
| PKM | Pyruvate kinase M | Downstream glycolytic enzyme; coordinates with hexokinase |
| OGT | O-GlcNAc transferase | Utilizes UDP-GlcNAc from hexosamine pathway; hexokinase feeds this pathway |
How Is hexokinase activity Regulated?
Hexokinase activity is regulated at multiple levels: transcriptionally by HIF1A and MYC, post-translationally by AKT-mediated phosphorylation of HK2, and through redox modifications of cysteine residues. Mitochondrial association of HK1 and HK2 via VDAC enhances activity and couples glycolysis to mitochondrial metabolism. Additionally, hexokinase activity can be inhibited by its product glucose-6-phosphate and by pharmacological agents like 2-deoxyglucose. In immune cells, HK2 expression is induced by inflammatory stimuli and metabolic stress, linking hexokinase activity to histone lactylation and inflammation.
hexokinase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| HK2 | Colorectal cancer | HK2 knockout in tumor-associated macrophages or cancer cells |
| HK2 | Inflammatory bowel disease | Intestinal epithelial cell-specific HK2 knockout |
| HK2 | MASLD | Liver macrophage-specific HK2 knockout or overexpression |
| HK1 | Metabolic disorders | HK1 knockout in skeletal muscle or liver |
| GCK | Maturity-onset diabetes of the young (MODY2) | GCK point mutations knock-in in pancreatic beta cells |
Cancer metabolism
Hexokinase 2 (HK2) is overexpressed in many cancers and is a key mediator of the Warburg effect, supporting rapid tumor growth. HK2 senses fructose in tumor-associated macrophages to promote colorectal cancer growth. Targeting HK2 or its mitochondrial binding has shown therapeutic potential in preclinical models.
Inflammatory bowel disease (IBD)
Hexokinase 2 expression in apical enterocytes correlates with inflammation severity in IBD patients. Microbial regulation of HK2 links mitochondrial metabolism and cell death in colitis, suggesting that hexokinase activity modulates intestinal inflammation.
Metabolic dysfunction-associated steatotic liver disease (MASLD)
Hexokinase 2-mediated metabolic stress and inflammation burden in liver macrophages via histone lactylation contribute to MASLD pathogenesis. This highlights hexokinase activity as a potential target in fatty liver disease.
Neuroinflammation and neurodegeneration
Dual roles of hexokinase 2 in shaping microglial function by gating glycolytic flux and mitochondrial activity suggest involvement in neuroinflammatory conditions. Dysregulated microglial metabolism is implicated in neurodegenerative diseases.
From hexokinase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does HK2 knockout affect tumor growth? | HK2 conditional knockout in mouse cancer models |
| How does HK2 mitochondrial binding regulate apoptosis? | HK2 point mutation (e.g., preventing AKT phosphorylation) knock-in |
| What is the role of HK2 in microglial function? | HK2 knockout in microglia or myeloid-specific knockout |
| Does fructose sensing by HK2 promote colorectal cancer? | HK2 knock-in with mutated fructose-binding site |
| How does HK2 histone lactylation affect MASLD? | HK2 overexpression or knockout in liver macrophages |
| Can HK2 inhibition ameliorate colitis? | Inducible HK2 knockout in intestinal epithelium |
How to Study the hexokinase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Coupled enzymatic assay | Hexokinase activity via NADPH production | Quantify enzyme activity in lysates |
| Seahorse XF analysis | Extracellular acidification rate (glycolysis) | Measure glycolytic flux in live cells |
| 13C-glucose tracing | Metabolic fate of glucose carbons | Assess pathway contributions |
| RNA-seq | mRNA expression levels of hexokinase isoforms | Compare expression across conditions |
| Western blot | Protein levels and phosphorylation status | Validate HK2 expression and modifications |
| Immunohistochemistry | Tissue localization and expression | Correlate with disease severity |
| CRISPR knockout screening | Gene essentiality and synthetic lethality | Identify modifiers of hexokinase dependency |
| Histone lactylation assay | Lactyl-lysine modifications | Link hexokinase activity to epigenetic changes |
Enzymatic activity assays
Hexokinase activity is typically measured using coupled enzyme assays that monitor NADPH production at 340 nm. These assays use glucose-6-phosphate dehydrogenase to couple glucose-6-phosphate formation to NADPH generation. Such methods are essential for quantifying hexokinase activity in cell lysates or purified fractions.
Metabolic flux analysis
Seahorse extracellular flux analysis and 13C-glucose tracing measure glycolytic flux and substrate utilization in live cells. These techniques have been used to demonstrate that HK2 gates glycolytic flux in microglia and tumor-associated macrophages.
Gene expression and proteomics
RNA-seq and quantitative proteomics (e.g., mass spectrometry) are used to assess hexokinase isoform expression and post-translational modifications. For example, HK2 expression in IBD patients was analyzed by RNA-seq and immunohistochemistry.
CRISPR screening and functional genomics
Genome-wide CRISPR knockout screens can identify genes that modulate hexokinase activity or sensitivity to hexokinase inhibitors. Such screens have been applied to discover metabolic vulnerabilities in cancer cells.
How CRISPR Can Be Used to Study GO:0004396 hexokinase activity
Knockout
CRISPR knockout of HK1, HK2, or other hexokinase genes enables loss-of-function studies to determine their roles in glycolysis, cell survival, and disease. For example, HK2 knockout in microglia revealed its dual role in glycolytic flux and mitochondrial activity. Similarly, HK2 knockout in tumor-associated macrophages reduced colorectal cancer growth.
Point Mutation
Point mutations can be introduced to dissect specific residues involved in catalysis, substrate binding, or post-translational regulation. For instance, mutating the AKT phosphorylation site on HK2 prevents its mitochondrial binding, affecting apoptosis. Such models are valuable for understanding isoform-specific functions.
Knock-in
Knock-in of tagged or mutant hexokinase alleles allows precise tracking of protein localization and dynamics. Tagged HK2 knock-in models can be used to study its interaction with VDAC and mitochondria in real time. Knock-in of disease-associated mutations (e.g., in GCK) models human metabolic disorders.
Overexpression
Overexpression of hexokinase isoforms via CRISPR activation or lentiviral vectors can mimic pathological states such as cancer or inflammation. HK2 overexpression in liver macrophages exacerbated MASLD via histone lactylation. Overexpression models help identify downstream effects and therapeutic targets.
How EDITGENE Supports hexokinase activity Research
Researchers studying hexokinase activity-related genes often need to determine whether a candidate gene is causally involved in metabolic regulation, disease progression, or therapeutic response. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell models, enabling functional validation of hexokinase isoforms and their regulators.
Contact EDITGENE today to design your custom CRISPR model for hexokinase activity research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| HK3 Knockout HEK293 Cell Line | EDJ-KQ916 | Human | 3101 | Details Get a Quote |
| HK1 Knockout HEK293 Cell Line | EDJ-KQ1506 | Human | 3098 | Details Get a Quote |
| HK2 Knockout HEK293 Cell Line | EDJ-KQ1507 | Human | 3099 | Details Get a Quote |
| HKDC1 Knockout HEK293 Cell Line | EDJ-KQ1508 | Human | 80201 | Details Get a Quote |
| GCK Knockout HEK293 Cell Line | EDJ-KQ3139 | Human | 2645 | Details Get a Quote |
| HK1 Knockout A-549 Cell Line | EDJ-KQ21124 | Human | 3098 | Details Get a Quote |
| HK1 Knockout HCT 116 Cell Line | EDJ-KQ21125 | Human | 3098 | Details Get a Quote |
| HK1 Knockout HeLa Cell Line | EDJ-KQ21126 | Human | 3098 | Details Get a Quote |
| HK2 Knockout HCT 116 Cell Line | EDJ-KQ21127 | Human | 3099 | Details Get a Quote |
| HK2 Knockout HeLa Cell Line | EDJ-KQ21128 | Human | 3099 | Details Get a Quote |
| HKDC1 Knockout A-549 Cell Line | EDJ-KQ21129 | Human | 80201 | Details Get a Quote |
| HKDC1 Knockout HCT 116 Cell Line | EDJ-KQ19785 | Human | 80201 | Details Get a Quote |
| GCK Knockout HeLa Cell Line | EDJ-KQ53317 | Human | 2645 | Details Get a Quote |
| HK3 Knockout HeLa Cell Line | EDJ-KQ53517 | Human | 3101 | Details Get a Quote |
| HKDC1 Knockout HeLa Cell Line | EDJ-KQ57309 | Human | 80201 | Details Get a Quote |
Displaying Records 1 To 15 Of 20 Records
Frequently Asked Questions About hexokinase activity
What is hexokinase activity?
Hexokinase activity (GO:0004396) is the catalysis of the reaction ATP + D-hexose = ADP + D-hexose 6-phosphate, the first step of glycolysis.
What genes are involved in hexokinase activity?
Genes encoding hexokinases include HK1, HK2, HK3, and GCK (hexokinase 4), each with distinct tissue distribution and regulation.
How is hexokinase activity regulated?
It is regulated transcriptionally by HIF1A and MYC, post-translationally by AKT phosphorylation, and through redox modifications and mitochondrial binding.
What diseases are associated with hexokinase activity?
Dysregulated hexokinase activity is linked to cancer, inflammatory bowel disease, MASLD, and neuroinflammation.
What is the role of HK2 in cancer?
HK2 is overexpressed in many cancers, supports glycolytic flux, and promotes tumor growth, including colorectal cancer.
How can I measure hexokinase activity?
Common methods include coupled enzymatic assays measuring NADPH production, Seahorse flux analysis, and 13C-glucose tracing.
What are the different types of hexokinase?
Mammalian hexokinases include HK1 (ubiquitous), HK2 (insulin-sensitive), HK3 (neutrophils), and HK4/glucokinase (liver and pancreas).
How does hexokinase activity affect inflammation?
HK2-mediated metabolic stress and histone lactylation contribute to inflammation in MASLD and colitis.
Can hexokinase activity be targeted therapeutically?
Yes, HK2 inhibitors and genetic ablation are being explored in cancer and inflammatory disease models.
What CRISPR models are available for hexokinase research?
EDITGENE offers knockout, point mutation knock-in, tagged knock-in, and overexpression models for hexokinase genes and regulators.
Conclusion
Hexokinase activity (GO:0004396) is a central molecular function that governs glucose metabolism and is implicated in a wide range of diseases, from cancer to inflammatory and metabolic disorders. The distinct roles of hexokinase isoforms, particularly HK2, in immune cells and tumors highlight the need for precise genetic models to dissect their functions. CRISPR-based approaches, including knockout, knock-in, and overexpression, provide powerful tools to study hexokinase biology and identify therapeutic targets. EDITGENE offers comprehensive services to support these research efforts, enabling discoveries that could translate into novel treatments.
References
- 1. Hu Y et al.. 2022. Dual roles of hexokinase 2 in shaping microglial function by gating glycolytic flux and mitochondrial activity.. Nat Metab 4(12):1756-1774 PMID: 36536134
- 2. Yan H et al.. 2024. Hexokinase 2 senses fructose in tumor-associated macrophages to promote colorectal cancer growth.. Cell Metab 36(11):2449-2467.e6 PMID: 39471815
- 3. Li J et al.. 2025. Hexokinase 2-mediated metabolic stress and inflammation burden of liver macrophages via histone lactylation in MASLD.. Cell Rep 44(3):115350 PMID: 40014451
- 4. Hinrichsen F et al.. 2021. Microbial regulation of hexokinase 2 links mitochondrial metabolism and cell death in colitis.. Cell Metab 33(12):2355-2366.e8 PMID: 34847376
- 5. Vestergaard H. 1999. Studies of gene expression and activity of hexokinase, phosphofructokinase and glycogen synthase in human skeletal muscle in states of altered insulin-stimulated glucose metabolism.. Dan Med Bull 46(1):13-34 PMID: 10081651
- 6. Galina A et al.. 2000. Hexokinase activity alters sugar-nucleotide formation in maize root homogenates.. Phytochemistry 53(1):29-37 PMID: 10656404
- 7. Heneberg P. 2019. Redox Regulation of Hexokinases.. Antioxid Redox Signal 30(3):415-442 PMID: 29742915
- 8. Weber-Stiehl S et al.. 2024. Hexokinase 2 expression in apical enterocytes correlates with inflammation severity in patients with inflammatory bowel disease.. BMC Med 22(1):490 PMID: 39444028
