GO:0070273 phosphatidylinositol-4-phosphate binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0070273 phosphatidylinositol-4-phosphate binding describes the molecular function of selectively binding phosphatidylinositol-4-phosphate (PtdIns4P), a phosphoinositide phosphorylated at the 4' position of the inositol ring.
• PtdIns4P binding proteins decode membrane identity and recruit effectors to the trans-Golgi network, endosomes, autophagosomes and the plasma membrane.
• PtdIns4P binding is central to lysosomal repair, inflammasome activation, xenophagy and ion-channel trafficking.
• Acquired PtdIns4P transport can drive T-cell deterioration and leukemogenesis, linking this binding function to cancer.
• PtdIns4P binding is regulated by phosphoinositide kinases, phosphatases such as SAC1, and membrane lipid transfer proteins.
• CRISPR knockout, point-mutation, knock-in and overexpression models enable causal testing of PtdIns4P-binding proteins in disease.
Description
Phosphatidylinositol-4-phosphate (PtdIns4P) is a low-abundance membrane phosphoinositide that serves as a spatial and functional landmark on eukaryotic organelles. The Gene Ontology molecular function GO:0070273, phosphatidylinositol-4-phosphate binding, defines the selective interaction of a protein with PtdIns4P, a derivative of phosphatidylinositol in which the inositol ring is phosphorylated at the 4' position. Proteins that carry this activity translate the local concentration of PtdIns4P into recruitment, conformational change or enzymatic activation, thereby controlling membrane trafficking, organelle identity and signal transduction. For researchers, GO:0070273 is a practical annotation because it distinguishes genuine PtdIns4P effectors from proteins that merely reside in PtdIns4P-rich membranes. Experimental evidence shows that PtdIns4P binding underlies rapid lysosomal repair, NLRP3 inflammasome activation on the dispersed trans-Golgi network, autophagosomal xenophagy and KCNQ1/KCNE1 channel trafficking. Perturbation of these interactions is associated with inflammatory, infectious, cardiac and malignant phenotypes. Because PtdIns4P is dynamically generated and consumed by phosphoinositide kinases and phosphatases, its binding function is temporally and spatially regulated. This article integrates the QuickGO definition with verified PubMed literature to summarize the mechanism, key genes, disease links and CRISPR-based research methods relevant to GO:0070273.
phosphatidylinositol-4-phosphate binding At A Glance
| GO ID | GO:0070273 |
|---|---|
| GO term | phosphatidylinositol-4-phosphate binding |
| Ontology | molecular_function |
| Synonym | none listed in QuickGO |
| Definition | Binding to phosphatidylinositol-4-phosphate, a derivative of phosphatidylinositol in which the inositol ring is phosphorylated at the 4' position |
| Major function | Selective recognition of PtdIns4P to recruit or activate proteins at specific membranes |
| Representative ligands | Phosphatidylinositol-4-phosphate (PtdIns4P) |
| Representative processes | Lysosomal repair, inflammasome activation, xenophagy, ion-channel trafficking |
| Regulatory enzymes | Phosphatidylinositol phosphate kinases and SAC1 phosphatase |
| Disease relevance | Inflammation, infection, cardiac channelopathy and leukemogenesis |
What Is GO:0070273?
GO:0070273 phosphatidylinositol-4-phosphate binding is a molecular function term describing the binding of a protein or molecular complex to phosphatidylinositol-4-phosphate, a phosphoinositide in which the inositol ring of phosphatidylinositol is phosphorylated at the 4' position. The term captures the selective recognition event itself rather than downstream signaling, transport or catalysis. Proteins annotated with this function often use PtdIns4P as a membrane anchor or allosteric cue to localize to the trans-Golgi network, endosomes, autophagosomes or the plasma membrane.
Why Is phosphatidylinositol-4-phosphate binding Important in Cell Biology?
GO:0070273 matters because PtdIns4P binding is a decisive step that converts a lipid gradient into a biological action. Without selective PtdIns4P recognition, cells fail to repair damaged lysosomes, activate the NLRP3 inflammasome, clear intracellular bacteria through xenophagy or correctly traffic KCNQ1/KCNE1 channels. The same binding function can be hijacked in disease, as acquired PtdIns4P transport initiates T-cell deterioration and leukemogenesis. Therefore, annotating and experimentally testing PtdIns4P-binding proteins is essential for understanding membrane biology and for identifying therapeutic targets.
• Defines membrane identity at the trans-Golgi network and endosomes.
• Enables rapid lysosomal repair after damage.
• Drives NLRP3 inflammasome activation on dispersed trans-Golgi network membranes.
• Supports autophagosomal PtdIns4P regulation during xenophagy.
• Controls KCNQ1/KCNE1 membrane expression and cardiac ion-channel physiology.
• Is subverted in T-cell leukemogenesis through acquired PtdIns4P transport.
• Provides a druggable interface for anti-inflammatory and anti-infective strategies.
• Requires phosphoinositide kinases and SAC1 for dynamic regulation.
• Can be studied with spatiotemporal PtdIns4P probes.
• Is amenable to CRISPR knockout, point-mutation, knock-in and overexpression modeling.
Molecular Mechanism of phosphatidylinositol-4-phosphate binding
PtdIns4P generation and membrane presentation
In simple terms: Cells first make the lipid tag that the binding protein will recognize.
PtdIns4P is produced by phosphatidylinositol phosphate kinases and is enriched on specific organelle membranes, including the trans-Golgi network and autophagosomes. Its local concentration and accessibility determine where PtdIns4P-binding proteins can engage the membrane. Spatiotemporal analysis methods have been developed to visualize these dynamic PtdIns4P pools.
Selective recognition by PtdIns4P-binding domains
In simple terms: The binding protein has a pocket that fits PtdIns4P and not other lipids.
Proteins annotated with GO:0070273 recognize the 4' phosphate of the inositol ring, which distinguishes PtdIns4P from other phosphoinositides. This selective interaction recruits effectors to PtdIns4P-rich membranes and can trigger conformational changes or enzymatic activation. For example, PtdIns4P on the dispersed trans-Golgi network mediates NLRP3 inflammasome activation by recruiting relevant machinery.
Effector recruitment and downstream action
In simple terms: Once bound, the protein carries out its job at that membrane.
PtdIns4P binding enables diverse downstream actions, including lysosomal repair, autophagosomal xenophagy and ion-channel trafficking. In lysosomal repair, a phosphoinositide signaling pathway rapidly responds to membrane damage. In xenophagy, SAC1 regulates autophagosomal PtdIns4P to direct bacterial clearance. In cardiac cells, membrane pools of PtdIns4P regulate KCNQ1/KCNE1 membrane expression.
Regulation by kinases, phosphatases and lipid transfer
In simple terms: Other proteins add or remove the lipid tag to switch binding on or off.
Phosphatidylinositol phosphate kinases generate PtdIns4P, while phosphatases such as SAC1 remove it, thereby controlling the availability of the binding site. Acquired PtdIns4P transport can also redistribute the lipid to new membranes, initiating T-cell deterioration and leukemogenesis. These regulatory layers ensure that PtdIns4P binding is spatially and temporally restricted.
Cofactors and membrane context
In simple terms: The lipid environment and partner proteins help the binding happen correctly.
PtdIns4P binding often occurs in the context of specific membrane compositions and partner proteins. For instance, PA binding of phosphatidylinositol 4-phosphate 5-kinase illustrates how lipid-protein interactions modulate phosphoinositide metabolism. Membrane pools of PtdIns4P regulate KCNQ1/KCNE1 expression, indicating that the local lipid context is functionally important.
Key Genes Involved in GO:0070273 phosphatidylinositol-4-phosphate binding
The following genes and proteins are experimentally linked to PtdIns4P binding, its regulation or its downstream biology.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NLRP3 | Inflammasome sensor activated by PtdIns4P on dispersed trans-Golgi network | Inflammation and innate immunity |
| SAC1 | Phosphatase regulating autophagosomal PtdIns4P | Xenophagy and bacterial clearance |
| KCNQ1 | Potassium channel whose membrane expression depends on PtdIns4P pools | Cardiac channel physiology |
| KCNE1 | Beta-subunit of KCNQ1 regulated by PtdIns4P | Cardiac channel physiology |
| PIP5K | Phosphatidylinositol 4-phosphate 5-kinase that binds PA and PtdIns4P | Phosphoinositide metabolism |
| PtdIns4P kinases | Enzymes that generate PtdIns4P | Lipid signaling |
| Lysosomal repair effectors | Proteins recruited by phosphoinositide signaling to damaged lysosomes | Membrane repair |
| T-cell leukemogenesis effectors | Proteins mediating acquired PtdIns4P transport | Leukemia research |
| PtdIns4P probes | Genetically encoded sensors for PtdIns4P dynamics | Spatiotemporal imaging |
| Golgi trafficking proteins | Effectors recruited to trans-Golgi PtdIns4P | Membrane trafficking |
| Autophagy proteins | Factors coordinating PtdIns4P during xenophagy | Host-pathogen defense |
| Ion channel complexes | Channels regulated by PtdIns4P binding | Electrophysiology |
| Phosphoinositide phosphatases | Enzymes that terminate PtdIns4P signals | Signal termination |
| Lipid transfer proteins | Proteins that move PtdIns4P between membranes | Leukemogenesis |
| Inflammasome adaptors | Proteins linking PtdIns4P to NLRP3 activation | Inflammation |
| Membrane repair machinery | Components responding to lysosomal damage | Cell stress |
| PtdIns4P-binding domains | Modular domains recognizing PtdIns4P | Protein engineering |
| SAC1-regulated effectors | Proteins controlled by SAC1 activity | Autophagy |
How Is phosphatidylinositol-4-phosphate binding Regulated?
PtdIns4P binding is regulated by the balance between phosphoinositide kinases and phosphatases. Phosphatidylinositol phosphate kinases synthesize PtdIns4P, while SAC1 dephosphorylates it to limit effector recruitment. Acquired PtdIns4P transport can redistribute the lipid and initiate T-cell deterioration and leukemogenesis. Membrane pools of PtdIns4P also regulate KCNQ1/KCNE1 expression, showing that the lipid environment itself is a regulatory layer. Spatiotemporal probes allow direct monitoring of these regulatory dynamics.
phosphatidylinositol-4-phosphate binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NLRP3 | Inflammasome activation and inflammation | Knockout and point-mutation macrophages |
| SAC1 | Xenophagy and bacterial clearance | Knockout epithelial cells |
| KCNQ1 | Cardiac channel expression | Knock-in and overexpression cardiomyocytes |
| KCNE1 | Cardiac channel expression | Knock-in and overexpression cardiomyocytes |
| PtdIns4P transport effectors | T-cell leukemogenesis | Overexpression and knockout T cells |
Inflammation and inflammasome activation
PtdIns4P on the dispersed trans-Golgi network mediates NLRP3 inflammasome activation, a central event in inflammatory disease. Proteins that bind PtdIns4P at this site are therefore candidate targets for anti-inflammatory intervention.
Infection and xenophagy
SAC1 regulates autophagosomal PtdIns4P for xenophagy-directed bacterial clearance, linking PtdIns4P binding to host defense against intracellular pathogens. Defects in this pathway can impair bacterial elimination.
Leukemogenesis
An acquired phosphatidylinositol 4-phosphate transport initiates T-cell deterioration and leukemogenesis, demonstrating that misregulated PtdIns4P binding or transport can drive malignancy.
Cardiac channelopathy
Membrane pools of PtdIns4P regulate KCNQ1/KCNE1 membrane expression, connecting PtdIns4P binding to cardiac ion-channel physiology and potentially to arrhythmia syndromes.
From phosphatidylinositol-4-phosphate binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a PtdIns4P-binding protein impair lysosomal repair? | CRISPR knockout cell line |
| Does a point mutation in a PtdIns4P-binding domain alter inflammasome activation? | Point-mutation knock-in |
| Does acquired PtdIns4P transport drive leukemogenesis? | Overexpression and knockout T cells |
| Does SAC1 loss affect autophagosomal PtdIns4P and xenophagy? | Knockout epithelial cells |
| Does PtdIns4P binding regulate KCNQ1/KCNE1 trafficking? | Knock-in and overexpression cardiomyocytes |
| Can PtdIns4P dynamics be visualized in live cells? | Tagged knock-in with PtdIns4P probes |
How to Study the phosphatidylinositol-4-phosphate binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Spatiotemporal PtdIns4P imaging | Dynamic PtdIns4P distribution | Organelle membrane dynamics |
| Lipid overlay and binding assays | Selective PtdIns4P binding | Domain specificity |
| CRISPR knockout | Loss-of-function phenotype | Causal testing |
| Point-mutation knock-in | Effect of binding-site mutation | Mechanism dissection |
| Overexpression | Gain-of-function phenotype | Leukemogenesis modeling |
| Electrophysiology | Ion-channel activity | Cardiac channel regulation |
| Autophagy flux assays | Xenophagy efficiency | Bacterial clearance |
| Inflammasome activation assays | NLRP3-dependent cytokine release | Inflammation |
Spatiotemporal PtdIns4P imaging
Genetically encoded probes and spatiotemporal analysis methods allow direct visualization of PtdIns4P dynamics on organelle membranes. These approaches are essential for linking binding events to membrane remodeling.
Lipid-protein interaction assays
Biochemical assays can test selective binding of candidate proteins to PtdIns4P versus other phosphoinositides. Such assays help validate GO:0070273 annotations.
Functional knockout and rescue
CRISPR knockout followed by rescue with wild-type or binding-deficient mutants can establish causality for PtdIns4P-binding proteins in lysosomal repair, inflammasome activation and xenophagy.
Electrophysiology and trafficking assays
Membrane expression and channel activity of KCNQ1/KCNE1 can be measured to test how PtdIns4P binding regulates ion-channel trafficking.
How CRISPR Can Be Used to Study GO:0070273 phosphatidylinositol-4-phosphate binding
Knockout
CRISPR knockout of genes encoding PtdIns4P-binding proteins or regulators such as SAC1 can reveal loss-of-function phenotypes in lysosomal repair, xenophagy and inflammasome activation. Knockout models are the first step to establish whether a candidate gene is required for the process.
Point Mutation
Point-mutation knock-in can disrupt the PtdIns4P-binding interface while preserving protein expression, allowing precise testing of the binding function itself. This is particularly useful for distinguishing binding-dependent from binding-independent roles.
Knock-in
Tagged knock-in of PtdIns4P-binding proteins or PtdIns4P probes enables live-cell imaging of localization and dynamics. Knock-in of disease-associated variants can model cardiac channel regulation by PtdIns4P.
Overexpression
Overexpression of PtdIns4P transport effectors can initiate T-cell deterioration and leukemogenesis, providing a gain-of-function model for cancer research. Overexpression of KCNQ1/KCNE1 can test how PtdIns4P pools regulate membrane expression.
How EDITGENE Supports phosphatidylinositol-4-phosphate binding Research
Researchers studying phosphatidylinositol-4-phosphate binding-related genes often need to determine whether a candidate gene is causally involved in lysosomal repair, inflammasome activation, xenophagy, ion-channel trafficking or leukemogenesis. EDITGENE provides the CRISPR cell models and bioinformatics support required to move from correlation to mechanism.
Contact EDITGENE today to design your custom CRISPR model for phosphatidylinositol-4-phosphate binding research.
Frequently Asked Questions About phosphatidylinositol-4-phosphate binding
What is phosphatidylinositol-4-phosphate binding?
It is the molecular function GO:0070273, describing selective binding to phosphatidylinositol-4-phosphate, a phosphoinositide phosphorylated at the 4' position of the inositol ring.
What is the GO ID for phosphatidylinositol-4-phosphate binding?
The GO ID is GO:0070273, a molecular_function term.
What genes are involved in phosphatidylinositol-4-phosphate binding?
Genes and proteins include NLRP3, SAC1, KCNQ1, KCNE1 and PIP5K, among others.
What processes depend on phosphatidylinositol-4-phosphate binding?
Lysosomal repair, NLRP3 inflammasome activation, xenophagy and KCNQ1/KCNE1 trafficking depend on PtdIns4P binding.
How is phosphatidylinositol-4-phosphate binding regulated?
It is regulated by phosphatidylinositol phosphate kinases, phosphatases such as SAC1, and lipid transport proteins.
Is phosphatidylinositol-4-phosphate binding linked to cancer?
Yes, acquired PtdIns4P transport initiates T-cell deterioration and leukemogenesis.
How can I study phosphatidylinositol-4-phosphate binding with CRISPR?
CRISPR knockout, point-mutation knock-in, tagged knock-in and overexpression models can test the function of PtdIns4P-binding proteins.
What methods visualize phosphatidylinositol-4-phosphate dynamics?
Spatiotemporal analysis with genetically encoded probes allows visualization of PtdIns4P dynamics.
Does phosphatidylinositol-4-phosphate binding affect the immune system?
Yes, PtdIns4P on the dispersed trans-Golgi network mediates NLRP3 inflammasome activation.
Does phosphatidylinositol-4-phosphate binding affect the heart?
Membrane pools of PtdIns4P regulate KCNQ1/KCNE1 membrane expression, which is important for cardiac ion-channel physiology.
Conclusion
GO:0070273 phosphatidylinositol-4-phosphate binding is a molecular function that converts a lipid landmark into recruitment and action at specific membranes. It is required for lysosomal repair, inflammasome activation, xenophagy and ion-channel trafficking, and it can be subverted in leukemogenesis. CRISPR-based knockout, point-mutation, knock-in and overexpression models, combined with imaging and bioinformatics, provide a rigorous path to test causality for PtdIns4P-binding proteins.
References
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- 2. Chen J et al.. 2018. PtdIns4P on dispersed trans-Golgi network mediates NLRP3 inflammasome activation.. Nature 564(7734):71-76 PMID: 30487600
- 3. Giudici ML et al.. 2004. Phosphatidylinositol phosphate kinases.. J Endocrinol Invest 27(6 Suppl):137-42 PMID: 15481814
- 4. Zhong W et al.. 2022. An acquired phosphatidylinositol 4-phosphate transport initiates T-cell deterioration and leukemogenesis.. Nat Commun 13(1):4390 PMID: 35906240
- 5. Stace C et al.. 2008. PA binding of phosphatidylinositol 4-phosphate 5-kinase.. Adv Enzyme Regul 48:55-72 PMID: 18167315
- 6. Liu K et al.. 2021. SAC1 regulates autophagosomal phosphatidylinositol-4-phosphate for xenophagy-directed bacterial clearance.. Cell Rep 36(4):109434 PMID: 34320354
- 7. Kawasaki A et al.. 2026. Spatiotemporal analysis of phosphatidylinositol 4-phosphate dynamics.. Methods Enzymol 726:143-155 PMID: 41720526
- 8. Braun C et al.. 2021. Membrane pools of phosphatidylinositol-4-phosphate regulate KCNQ1/KCNE1 membrane expression.. Commun Biol 4(1):1392 PMID: 34907346
