GO:0016868 intramolecular phosphotransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0016868 defines intramolecular phosphotransferase activity, the catalysis of phosphate transfer from one position to another within a single molecule.
• This activity is also known as phosphomutase activity and is distinct from intermolecular kinases that transfer phosphate between separate molecules.
• Intramolecular phosphotransferases regulate signaling proteins such as Jak3, where tyrosine 820 mediates intramolecular negative regulation.
• Disruption of intramolecular interactions, as seen for AKT, can lead to constitutive activation in cancer.
• Studying this activity requires methods that detect phosphate migration, such as phosphoproteomics and site-directed mutagenesis.
• CRISPR-based knockout, point mutation, and knock-in models are essential to dissect the functional consequences of intramolecular phosphotransferase activity.
Description
Intramolecular phosphotransferase activity (GO:0016868) is a molecular function that catalyzes the transfer of a phosphate group from one position to another within a single molecule. This activity is fundamental to cellular signaling and metabolism, as it can alter the conformation and activity of proteins and other biomolecules. Unlike kinases that phosphorylate separate substrate molecules, intramolecular phosphotransferases act within the same molecule, often as part of autoregulatory loops. Understanding this activity is crucial for researchers studying signal transduction, enzyme regulation, and disease mechanisms. For example, the intramolecular negative regulation of mouse Jak3 by tyrosine 820 highlights how a single residue can control kinase activity through intramolecular interactions. Similarly, zinc ions can activate AKT by disrupting intramolecular interactions, promoting prostate cancer cell proliferation. These examples underscore the importance of GO:0016868 in both normal physiology and disease. This article provides a comprehensive overview of the definition, mechanisms, key genes, and research methods associated with intramolecular phosphotransferase activity, optimized for both human readers and AI-driven retrieval.
intramolecular phosphotransferase activity At A Glance
| GO ID | GO:0016868 |
|---|---|
| GO term | intramolecular phosphotransferase activity |
| Ontology | molecular_function |
| Synonym | phosphomutase activity; intramolecular transferase activity, phosphotransferases; phosphotransferase activity, with regeneration of donors, apparently catalyzing intramolecular transfers |
| Major function | Catalysis of phosphate group transfer within a single molecule |
| EC number | Not specified in QuickGO |
| Related activity | Intramolecular transferase activity (GO:0016866) |
What Is GO:0016868?
Intramolecular phosphotransferase activity (GO:0016868) is defined as the catalysis of the transfer of a phosphate group from one position to another within a single molecule. This activity is synonymous with phosphomutase activity and intramolecular transferase activity, phosphotransferases. It is a molecular function that does not involve the transfer of phosphate between different molecules, distinguishing it from typical kinase activities.
Why Is intramolecular phosphotransferase activity Important in Cell Biology?
Intramolecular phosphotransferase activity is critical for regulating protein function and cellular signaling. It enables autoregulatory mechanisms, such as the intramolecular negative regulation of Jak3 by tyrosine 820, which controls kinase activity and downstream signaling. Disruption of intramolecular interactions can lead to pathological activation of proteins like AKT, contributing to cancer progression. Therefore, understanding this activity provides insights into disease mechanisms and potential therapeutic targets.
• Regulates kinase activity through intramolecular interactions, as seen in Jak3.
• Disruption of intramolecular regulation can lead to constitutive activation of oncoproteins like AKT.
• Involved in metabolic pathways where phosphate migration alters metabolite function.
• Plays a role in signal transduction cascades, affecting cell growth and survival.
• Provides targets for therapeutic intervention in cancers and immune disorders.
• Essential for understanding enzyme autoregulation and allosteric mechanisms.
• Can be studied using phosphoproteomics and site-directed mutagenesis.
• CRISPR models enable precise dissection of intramolecular phosphotransferase function.
Molecular Mechanism of intramolecular phosphotransferase activity
Substrate Recognition and Binding
In simple terms: The enzyme first binds to its substrate molecule, positioning the phosphate group for transfer.
Intramolecular phosphotransferases recognize specific structural features within the same molecule. For example, in Jak3, tyrosine 820 acts as a regulatory site that interacts with the kinase domain to inhibit activity. This binding is often mediated by intramolecular interactions that stabilize an autoinhibitory conformation.
Catalytic Transfer of Phosphate
In simple terms: The enzyme moves the phosphate group from one part of the molecule to another.
The catalytic mechanism involves the transfer of a phosphate group from a donor residue (e.g., a phosphorylated tyrosine) to an acceptor residue within the same molecule. This process can be mediated by conformational changes that bring the donor and acceptor sites into proximity. In AKT, zinc ions disrupt intramolecular interactions, leading to activation and subsequent phosphorylation events.
Regulation by Intramolecular Interactions
In simple terms: The enzyme's activity can be turned on or off by interactions within the same molecule.
Intramolecular interactions, such as those involving tyrosine 820 in Jak3, can negatively regulate kinase activity. Disruption of these interactions, for instance by zinc ions in AKT, can relieve autoinhibition and promote activity. This regulation is crucial for maintaining cellular homeostasis.
Cofactors and Modulators
In simple terms: Other molecules can influence the enzyme's ability to transfer phosphate.
Metal ions such as zinc can modulate intramolecular phosphotransferase activity by disrupting intramolecular interactions. In AKT, zinc ions activate the kinase by disrupting an intramolecular interaction, promoting prostate cancer cell proliferation. Other cofactors may include ATP or other phosphate donors, though specific cofactors for many intramolecular phosphotransferases remain to be fully characterized.
Key Genes Involved in GO:0016868 intramolecular phosphotransferase activity
The following genes and proteins are associated with intramolecular phosphotransferase activity or related regulatory mechanisms, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| JAK3 | Tyrosine kinase with intramolecular negative regulation by Y820 | Study of autoinhibition and immune signaling |
| AKT1 | Serine/threonine kinase regulated by intramolecular interactions | Cancer research, zinc-induced activation |
| DAPK1 | Calcium/calmodulin-dependent kinase with intramolecular regulation | Apoptosis and autophagy |
| CDK4 | Cyclin-dependent kinase involved in cell cycle | Cancer therapy and immune regulation |
| CDK6 | Cyclin-dependent kinase partnering with CDK4 | Cancer and immune cell function |
| MIF | Macrophage migration inhibitory factor, cytokine | Inflammation and cancer |
| CDKN1A | P21, cyclin-dependent kinase inhibitor | Thyroid carcinoma susceptibility |
| PAK4 | P21-activated kinase 4 | Familial non-medullary thyroid carcinoma |
| EGFR | Epidermal growth factor receptor | Cell proliferation and cancer |
| GSDMD | Gasdermin D, mediator of pyroptosis | Inflammation and lupus |
| P38 MAPK | Stress-activated kinase | Inflammatory signaling |
| JAK3 Y820 | Regulatory tyrosine residue | Intramolecular regulation |
| AKT PH domain | Pleckstrin homology domain | Intramolecular interaction |
| Zinc ions | Metal modulator | AKT activation |
| MIF-p38 axis | Inflammatory loop | UVB-induced cutaneous lupus |
| CDK4/6 inhibitors | Pharmacological agents | Antitumor immunity |
| DAP-kinase interactome | Protein interaction network | Apoptosis regulation |
How Is intramolecular phosphotransferase activity Regulated?
Intramolecular phosphotransferase activity is regulated by intramolecular interactions that stabilize autoinhibitory conformations. For example, in Jak3, tyrosine 820 mediates intramolecular negative regulation, and its mutation can lead to increased kinase activity. In AKT, zinc ions disrupt intramolecular interactions, leading to activation. Additionally, CDK4/6 inhibition can modulate immune responses through MIF, suggesting crosstalk between cell cycle regulation and intramolecular phosphotransferase activity.
intramolecular phosphotransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| AKT1 | Prostate cancer | Point mutation of zinc-binding site; overexpression |
| JAK3 | Immune disorders | Knock-in of Y820F mutation |
| CDK4/6 | Cancer and antitumor immunity | Knockout and inhibitor treatment |
| PAK4 | Familial non-medullary thyroid carcinoma | Knockout and point mutation |
| MIF | Cutaneous lupus and acute kidney injury | Knockout and overexpression |
Cancer
Dysregulation of intramolecular phosphotransferase activity can contribute to cancer. For instance, zinc ions activate AKT by disrupting intramolecular interactions, promoting prostate cancer cell proliferation. CDK4/6 inhibition induces antitumor immunity via MIF, highlighting the role of intramolecular regulation in cancer therapy. PAK4 has been identified as a susceptibility gene for familial non-medullary thyroid carcinoma.
Inflammatory and Autoimmune Diseases
Intramolecular phosphotransferase activity is implicated in inflammatory conditions. A MIF-p38-GSDMD inflammatory loop in keratinocytes underlies UVB-induced cutaneous lupus, suggesting that intramolecular signaling contributes to autoimmune skin diseases. Macrophage migration inhibitory factor (MIF) has biphasic protective effects in ischemia/reperfusion-induced acute kidney injury, indicating complex regulation.
Apoptosis and Neurodegeneration
DAP-kinase, a calcium/calmodulin-dependent kinase with intramolecular regulation, is involved in apoptosis and autophagy. Its interactome provides insights into how intramolecular phosphotransferase activity may influence cell death pathways relevant to neurodegeneration.
From intramolecular phosphotransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does Y820 phosphorylation regulate Jak3 activity? | Point mutation (Y820F) knock-in |
| How does zinc activate AKT? | Point mutation of zinc-binding residues; overexpression |
| What is the role of CDK4/6 in antitumor immunity? | Knockout and conditional knockout |
| Is PAK4 a susceptibility gene for thyroid carcinoma? | Knockout and point mutation |
| How does MIF contribute to lupus? | Knockout and overexpression |
| What is the function of DAP-kinase interactome? | Tagged knock-in and knockout |
How to Study the intramolecular phosphotransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Phosphoproteomics | Global phosphorylation sites | Identify intramolecular phosphotransferase targets |
| Site-directed mutagenesis | Effect of specific point mutations | Test regulatory residues |
| CRISPR-Cas9 knockout | Loss of gene function | Determine necessity in disease models |
| CRISPR knock-in | Introduction of specific mutations | Model disease-associated variants |
| Co-immunoprecipitation | Protein-protein interactions | Study intramolecular interactions |
| Western blotting | Protein expression and phosphorylation | Validate changes in signaling |
| Kinase activity assay | Enzymatic activity | Measure intramolecular phosphotransferase activity |
| RNA-seq | Transcriptional changes | Assess downstream effects |
Phosphoproteomics
Phosphoproteomics allows global identification and quantification of phosphorylation sites, including those involved in intramolecular phosphotransferase activity. This method can reveal changes in phosphorylation patterns upon perturbation of regulatory residues, such as Y820 in Jak3.
Site-Directed Mutagenesis
Site-directed mutagenesis is used to introduce point mutations that disrupt or mimic phosphorylation, enabling functional studies of intramolecular phosphotransferase activity. For example, mutating Y820 in Jak3 to phenylalanine abolishes negative regulation.
CRISPR-Cas9 Genome Editing
CRISPR-Cas9 enables precise knockout, knock-in, or point mutation of genes encoding intramolecular phosphotransferases or their regulatory residues. This approach is essential for dissecting causal roles in disease models.
Protein-Protein Interaction Assays
Co-immunoprecipitation and proximity ligation assays can detect intramolecular interactions and conformational changes. These methods help elucidate how intramolecular phosphotransferase activity is regulated by binding partners.
How CRISPR Can Be Used to Study GO:0016868 intramolecular phosphotransferase activity
Knockout
CRISPR knockout of genes encoding intramolecular phosphotransferases, such as JAK3 or AKT1, can reveal their essential roles in signaling and disease. For example, CDK4/6 knockout models have been used to study antitumor immunity.
Point Mutation
Point mutations can be introduced to mimic or abolish phosphorylation at regulatory residues. The Y820F mutation in Jak3 is a classic example that disrupts intramolecular negative regulation. Similarly, mutations in AKT's zinc-binding site can prevent zinc-induced activation.
Knock-in
Knock-in of disease-associated variants or tagged versions of proteins allows tracking of intramolecular phosphotransferase activity in vivo. This approach is useful for studying PAK4 variants in thyroid carcinoma.
Overexpression
Overexpression of wild-type or mutant intramolecular phosphotransferases can model gain-of-function effects. For instance, overexpression of MIF has been used to study its role in lupus and kidney injury.
How EDITGENE Supports intramolecular phosphotransferase activity Research
Researchers studying intramolecular phosphotransferase activity-related genes often need to determine whether a candidate gene is causally involved in a specific biological process or disease. This requires precise genetic manipulation, which can be achieved through CRISPR-based models.
Contact EDITGENE today to design your custom CRISPR model for intramolecular phosphotransferase activity research.
Frequently Asked Questions About intramolecular phosphotransferase activity
What is intramolecular phosphotransferase activity?
It is the catalysis of phosphate group transfer from one position to another within a single molecule, defined by GO:0016868.
What genes are involved in intramolecular phosphotransferase activity?
Genes such as JAK3, AKT1, and DAPK1 encode proteins with intramolecular phosphotransferase or regulatory activity.
How is intramolecular phosphotransferase activity regulated?
It is regulated by intramolecular interactions, such as the autoinhibitory interaction mediated by tyrosine 820 in Jak3.
What diseases are associated with intramolecular phosphotransferase activity?
Cancer, inflammatory diseases, and autoimmune conditions such as prostate cancer and cutaneous lupus.
What methods are used to study intramolecular phosphotransferase activity?
Phosphoproteomics, site-directed mutagenesis, and CRISPR-Cas9 genome editing are commonly used.
Can CRISPR be used to study intramolecular phosphotransferase activity?
Yes, CRISPR knockout, point mutation, and knock-in models enable precise functional studies.
What is the role of zinc in intramolecular phosphotransferase activity?
Zinc ions can disrupt intramolecular interactions in AKT, leading to activation and promoting prostate cancer cell proliferation.
How does CDK4/6 inhibition relate to intramolecular phosphotransferase activity?
CDK4/6 inhibition induces antitumor immunity via MIF, suggesting crosstalk with intramolecular regulatory pathways.
What is the significance of tyrosine 820 in Jak3?
Y820 mediates intramolecular negative regulation of Jak3 activity, and its mutation increases kinase activity.
Where can I find CRISPR models for intramolecular phosphotransferase research?
EDITGENE provides custom knockout, point mutation, knock-in, and overexpression models for related genes.
Conclusion
Intramolecular phosphotransferase activity (GO:0016868) is a critical molecular function that regulates protein activity through phosphate transfer within a single molecule. Its dysregulation is implicated in cancer, inflammatory diseases, and autoimmune conditions. Understanding its mechanisms and key genes, such as JAK3 and AKT1, requires advanced research tools including CRISPR-based models. EDITGENE offers comprehensive services to support such studies, from knockout and point mutation models to library screening and bioinformatics.
References
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- 3. Du Y et al.. 2025. Biphasic protective effects of macrophage migration inhibitory factor in ischemia/reperfusion-induced acute kidney injury.. Commun Biol 8(1):1112 PMID: 40721484
- 4. Jiang YJ et al.. 2024. Identification of P21 (CDKN1A) Activated Kinase 4 as a Susceptibility Gene for Familial Non-Medullary Thyroid Carcinoma.. Thyroid 34(5):583-597 PMID: 38411500
- 5. Sekine Y et al.. 2022. A novel intramolecular negative regulation of mouse Jak3 activity by tyrosine 820.. Int Immunol 34(6):303-312 PMID: 35192696
- 6. Gill GN et al.. 1987. Epidermal growth factor and its receptor.. Mol Cell Endocrinol 51(3):169-86 PMID: 3109978
- 7. Wang K et al.. 2025. Zinc ions activate AKT and promote prostate cancer cell proliferation via disrupting AKT intramolecular interaction.. Oncogene 44(1):8-18 PMID: 39438763
- 8. Guo C et al.. 2026. A MIF-p38-GSDMD inflammatory loop in keratinocytes underlies UVB-induced cutaneous lupus.. Cell Death Dis 17(1):198 PMID: 41629274
