GO:1902936 phosphatidylinositol bisphosphate binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1902936 phosphatidylinositol bisphosphate binding is a molecular function defined as binding to phosphatidylinositol bisphosphate, a key phosphoinositide lipid.
• This binding activity is critical for diverse cellular processes including migrasome formation, STING signaling, nuclear AKT activation, and cytokinetic abscission.
• Key proteins that bind phosphatidylinositol bisphosphate include Rab35, STING, annexin A2, p53, and PI(3,4)P2 effectors.
• Dysregulation of phosphatidylinositol bisphosphate binding is linked to cancer, immune disorders, and cataract formation.
• CRISPR knockout, point mutation, and knock-in models are essential to dissect the causal roles of these binding interactions.
• EDITGENE provides comprehensive CRISPR services to study phosphatidylinositol bisphosphate binding in disease and development.
Description
Phosphatidylinositol bisphosphate (PIP2) is a minor but critically important phospholipid in eukaryotic membranes. The molecular function of phosphatidylinositol bisphosphate binding (GO:1902936) refers to the selective interaction of proteins or other molecules with PIP2 or its isomers. This binding event is not merely a passive association; it serves as a dynamic signaling platform that recruits and regulates effector proteins at specific cellular locations. Understanding this function is fundamental for researchers studying membrane trafficking, signal transduction, and cytoskeletal dynamics. Recent studies have highlighted the role of PIP2 binding in processes as diverse as migrasome formation, innate immune signaling, and nuclear AKT activation. The binding is often mediated by specific structural domains, such as pleckstrin homology (PH) domains, and can be modulated by other lipids like cholesterol. Given its broad impact, phosphatidylinositol bisphosphate binding is a focal point for both basic cell biology and translational research in cancer, immunology, and ophthalmology.
phosphatidylinositol bisphosphate binding At A Glance
| GO ID | GO:1902936 |
|---|---|
| GO term | phosphatidylinositol bisphosphate binding |
| Ontology | molecular_function |
| Synonym | None |
| Major function | Binding to phosphatidylinositol bisphosphate, a key phosphoinositide lipid involved in signaling and membrane dynamics |
| Definition source | QuickGO |
| Related processes | Migrasome formation, STING signaling, nuclear AKT activation, cytokinetic abscission |
| Key proteins | Rab35, STING, annexin A2, p53, PI(3,4)P2 effectors |
What Is GO:1902936?
GO:1902936 phosphatidylinositol bisphosphate binding is a molecular function term in the Gene Ontology that describes the selective interaction of a molecule with phosphatidylinositol bisphosphate (PIP2). This includes binding to any phosphorylated derivative of phosphatidylinositol, such as phosphatidylinositol 4,5-bisphosphate (PIP2) or phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2). The binding can occur through specific protein domains and is often regulated by the local lipid environment.
Why Is phosphatidylinositol bisphosphate binding Important in Cell Biology?
Phosphatidylinositol bisphosphate binding is a central node in cellular signaling because PIP2 is a low-abundance lipid that can act as both a substrate and a docking site for numerous proteins. The binding event often triggers conformational changes or recruitment of signaling complexes that control cell shape, motility, and survival. For example, the PIP2-Rab35 axis is essential for migrasome formation, a recently discovered process involved in intercellular communication. Similarly, STING activation by phosphoinositides is critical for innate immunity, and its dysregulation can lead to autoinflammatory diseases. In the nucleus, p53-mediated PIP2 binding regulates AKT activation, linking lipid signaling to tumor suppression. Thus, understanding this function provides mechanistic insights into health and disease.
• Regulates migrasome formation, a process involved in cell-cell communication and organ morphogenesis.
• Controls STING activation in innate immunity, with implications for autoimmune and inflammatory diseases.
• Mediates nuclear AKT activation via a p53-phosphoinositide signalosome, impacting cancer cell survival.
• Essential for cytokinetic abscission; defects lead to early senescence and cataract formation.
• Modulates cytoskeletal dynamics through interactions with actin-capping proteins.
• Influences membrane homeostasis via phosphatidylinositol flippases.
• Targeted by small molecules like neomycin, which can disrupt PIP2 binding.
• Involved in cholesterol-dependent membrane organization through annexin A2.
• Provides a mechanism for spatial and temporal control of signaling at membranes.
• Offers potential therapeutic targets for cancer, immune disorders, and eye diseases.
Molecular Mechanism of phosphatidylinositol bisphosphate binding
Recognition and Binding to PIP2
In simple terms: Proteins find and attach to PIP2 lipids in the membrane.
The binding of proteins to phosphatidylinositol bisphosphate (PIP2) is mediated by specific structural domains, such as pleckstrin homology (PH) domains, which recognize the phosphorylated inositol headgroup. For instance, annexin A2 cooperatively binds to cholesterol- and PIP2-containing bilayers, suggesting that lipid composition influences binding affinity. The binding can be direct, as seen with neomycin, which binds PIP2 and can be used to study its function. This recognition is the first step in recruiting effector proteins to specific membrane microdomains.
Conformational Changes and Effector Recruitment
In simple terms: Binding causes proteins to change shape and bring in other partners.
Upon binding PIP2, proteins often undergo conformational changes that expose interaction surfaces or activate enzymatic activity. For example, the PIP2-Rab35 axis regulates migrasome formation, where Rab35 binding to PIP2 is required for the assembly of migrasomes. Similarly, STING activation by phosphoinositides involves binding that triggers downstream signaling. This step is critical for translating the lipid signal into a cellular response.
Signal Transduction and Downstream Effects
In simple terms: The binding event turns on signaling pathways that change cell behavior.
PIP2 binding can initiate signaling cascades. In the nucleus, a p53-phosphoinositide signalosome regulates AKT activation, where p53 binds PIP2 to facilitate AKT phosphorylation and activation. This leads to changes in gene expression and cell survival. In cytokinetic abscission, PI(3,4)P2-mediated processes are essential for the final separation of daughter cells, and defects cause early senescence and cataract formation. These downstream effects highlight the functional importance of PIP2 binding.
Regulation by Other Lipids and Proteins
In simple terms: Other molecules can help or hinder the binding to PIP2.
The binding of proteins to PIP2 is regulated by the local lipid environment, including cholesterol and other phosphoinositides. For example, cholesterol enhances annexin A2 binding to PIP2-containing bilayers. Additionally, phosphatidylinositol flippases contribute to phosphoinositide homeostasis in the plasma membrane, indirectly affecting PIP2 availability. Actin-capping proteins may also compete or cooperate with PIP2 binding to regulate cytoskeletal dynamics. This regulation ensures that PIP2 binding occurs at the right time and place.
Key Genes Involved in GO:1902936 phosphatidylinositol bisphosphate binding
The following genes encode proteins that bind phosphatidylinositol bisphosphate and are key to understanding this molecular function.
| Gene | Major Role | Research Relevance |
|---|---|---|
| RAB35 | Regulates migrasome formation via PIP2 binding | Studied in cell migration and intercellular communication |
| STING1 | Binds phosphoinositides for innate immune signaling | Target for autoimmune and inflammatory diseases |
| ANXA2 | Binds PIP2 and cholesterol in membranes | Involved in membrane repair and cancer |
| TP53 | Forms nuclear signalosome with PIP2 to activate AKT | Tumor suppressor with lipid signaling roles |
| PIK3C3 | Kinase that generates PI(3)P, related to PIP2 metabolism | Autophagy and endosomal trafficking |
| PTEN | Lipid phosphatase that dephosphorylates PIP3 to PIP2 | Tumor suppressor frequently mutated in cancer |
| INPP5D | Inositol polyphosphate-5-phosphatase, regulates PIP2 levels | Immune cell signaling |
| PLCB1 | Phospholipase C beta 1, hydrolyzes PIP2 | G-protein coupled receptor signaling |
| PLCG1 | Phospholipase C gamma 1, hydrolyzes PIP2 | Growth factor signaling |
| PIP5K1A | Phosphatidylinositol-4-phosphate 5-kinase, synthesizes PIP2 | Membrane trafficking |
| PIP5K1B | Another PIP2-synthesizing kinase | Cytoskeletal regulation |
| SYNJ1 | Synaptojanin 1, PIP2 phosphatase | Neurotransmission and Parkinson's disease |
| OCRL | Oculocerebrorenal syndrome of Lowe protein, PIP2 phosphatase | Lowe syndrome |
| AP2A1 | Adaptor protein complex 2, binds PIP2 for endocytosis | Clathrin-mediated endocytosis |
| DNM1 | Dynamin 1, binds PIP2 for membrane fission | Endocytosis and synaptic vesicle recycling |
| ACTB | Actin beta, interacts with PIP2-binding proteins | Cytoskeleton dynamics |
| CAPZA1 | F-actin capping protein, regulated by PIP2 | Actin filament assembly |
How Is phosphatidylinositol bisphosphate binding Regulated?
Phosphatidylinositol bisphosphate binding is regulated at multiple levels. The availability of PIP2 itself is controlled by enzymes such as phosphatidylinositol-4-phosphate 5-kinases (PIP5Ks) and phosphatases like PTEN and INPP5D. Additionally, the lipid environment, including cholesterol, can modulate binding affinity. Phosphatidylinositol flippases contribute to maintaining phosphoinositide homeostasis in the plasma membrane, thereby influencing PIP2 distribution. Furthermore, post-translational modifications of binding proteins, such as phosphorylation, can affect their interaction with PIP2. For example, the p53-phosphoinositide signalosome is regulated by cellular stress, leading to nuclear AKT activation. These regulatory mechanisms ensure that PIP2 binding is tightly controlled in space and time.
phosphatidylinositol bisphosphate binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| TP53 | Cancer, nuclear AKT activation | Knockout and point mutation in cancer cell lines |
| STING1 | Autoinflammatory diseases | Knock-in of patient mutations in immune cells |
| OCRL | Lowe syndrome | Knockout in renal cells |
| SYNJ1 | Parkinson's disease | Knock-in of disease-associated variants in neurons |
| PIK3C3 | Cancer, autophagy defects | Knockout in HeLa cells |
Cancer
Dysregulation of phosphatidylinositol bisphosphate binding is implicated in cancer. The p53-phosphoinositide signalosome regulates nuclear AKT activation, a pathway often hyperactivated in tumors. Mutations in TP53, which encodes p53, can disrupt this lipid signaling, contributing to oncogenesis. Additionally, PIP2-binding proteins such as PTEN are well-known tumor suppressors. Targeting these interactions may offer therapeutic opportunities.
Immune Disorders
STING activation by phosphoinositides is critical for innate immunity, and aberrant binding can lead to autoinflammatory diseases. Mutations in STING1 that affect its lipid binding cause constitutive activation, resulting in interferonopathies. Understanding the molecular details of PIP2 binding to STING could inform the development of inhibitors for these conditions.
Eye Diseases
PI(3,4)P2-mediated cytokinetic abscission is essential for lens development, and defects in this process cause early senescence and cataract formation. This highlights the importance of PIP2 binding in tissue homeostasis and provides a model for studying age-related eye diseases.
Neurological Disorders
Synaptojanin 1 (SYNJ1) is a PIP2 phosphatase that regulates synaptic vesicle recycling. Mutations in SYNJ1 are linked to Parkinson's disease, underscoring the role of PIP2 metabolism in neurodegeneration. Although direct binding of SYNJ1 to PIP2 is not its primary function, its activity modulates PIP2 levels, affecting binding partners.
From phosphatidylinositol bisphosphate binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does Rab35 binding to PIP2 drive migrasome formation? | RAB35 knockout and point mutation in HeLa cells |
| How does STING binding to phosphoinositides affect immune signaling? | STING1 knockout and knock-in in macrophages |
| What is the role of p53-PIP2 interaction in nuclear AKT activation? | TP53 knockout and point mutation in cancer cells |
| Does PI(3,4)P2 binding regulate cytokinetic abscission? | Knockout of PI(3,4)P2 effectors in lens epithelial cells |
| How does cholesterol modulate annexin A2 binding to PIP2? | ANXA2 overexpression and point mutation in model membranes |
| Can neomycin disrupt PIP2 binding in vivo? | Overexpression of PIP2-binding proteins and treatment with neomycin |
How to Study the phosphatidylinositol bisphosphate binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Liposome sedimentation | Direct binding affinity to PIP2 | In vitro validation of binding domains |
| Surface plasmon resonance | Kinetics of PIP2-protein interaction | Quantitative binding studies |
| Fluorescence microscopy | Subcellular localization and colocalization | Live-cell imaging of PIP2 and proteins |
| CRISPR knockout | Loss-of-function phenotype | Causal gene identification |
| Rescue with mutants | Specificity of binding | Structure-function analysis |
| AP-MS | Protein interaction network | Discovery of new PIP2 binders |
| Ribo-seq | Translation efficiency of binding proteins | Global regulation of expression |
| RNA-seq | Transcriptional changes upon perturbation | Pathway analysis |
Lipid Binding Assays
In vitro lipid binding assays, such as liposome sedimentation or surface plasmon resonance (SPR), can measure the affinity of proteins for PIP2. These methods use synthetic liposomes containing PIP2 and recombinant proteins. For example, the binding of neomycin to PIP2 was characterized using such assays. They are essential for quantifying direct interactions and testing the effects of mutations.
Cellular Imaging
Fluorescence microscopy with PIP2-specific probes (e.g., GFP-PH domains) can visualize PIP2 distribution and colocalization with binding proteins in live cells. This approach has been used to study migrasome formation and STING trafficking. Advanced techniques like total internal reflection fluorescence (TIRF) microscopy allow real-time observation of binding events at the plasma membrane.
Genetic Perturbation and Rescue
CRISPR knockout of genes encoding PIP2-binding proteins, followed by rescue with wild-type or binding-deficient mutants, can establish causality. For instance, knockout of RAB35 and rescue with PIP2-binding-deficient mutants demonstrated its role in migrasome formation. Similar strategies are used for STING and p53.
Proteomics and Interactomics
Affinity purification coupled with mass spectrometry (AP-MS) can identify proteins that bind PIP2 under specific conditions. This approach can reveal novel PIP2-binding proteins and their interaction networks. When combined with CRISPR screening, it can pinpoint functional interactions.
How CRISPR Can Be Used to Study GO:1902936 phosphatidylinositol bisphosphate binding
Knockout
CRISPR knockout of genes encoding PIP2-binding proteins is a powerful approach to study their function. For example, RAB35 knockout abolished migrasome formation, demonstrating its essential role. Similarly, STING1 knockout impaired innate immune signaling. Knockout cell lines can be generated in various backgrounds, including cancer and immune cells, to model disease.
Point Mutation
Introducing point mutations that specifically abrogate PIP2 binding without affecting other functions is critical for dissecting the precise contribution of the binding event. For instance, mutations in the PIP2-binding site of Rab35 can be knocked into the endogenous locus to test its role in migrasome formation. This approach avoids confounding effects from complete protein loss.
Knock-in
Knock-in of disease-associated mutations or tagged versions of proteins allows for physiological expression and real-time tracking. For example, knocking in a fluorescent tag on STING can reveal its trafficking upon PIP2 binding. Knock-in models are also useful for studying patient-specific mutations in TP53 that affect PIP2 binding.
Overexpression
Overexpression of wild-type or mutant PIP2-binding proteins can be used to test gain-of-function effects. For example, overexpression of annexin A2 enhanced its binding to PIP2-containing membranes. Overexpression systems are also valuable for biochemical purification of protein-lipid complexes.
How EDITGENE Supports phosphatidylinositol bisphosphate binding Research
Researchers studying phosphatidylinositol bisphosphate binding-related genes often need to determine whether a candidate gene is causally involved in a specific cellular process or disease. This requires precise genetic manipulation, which can be achieved through CRISPR-based knockout, point mutation, knock-in, or overexpression models. EDITGENE provides end-to-end services to generate such models and support functional studies.
Contact EDITGENE today to design your custom CRISPR model for phosphatidylinositol bisphosphate binding research.
Frequently Asked Questions About phosphatidylinositol bisphosphate binding
What is phosphatidylinositol bisphosphate binding?
Phosphatidylinositol bisphosphate binding (GO:1902936) is a molecular function where a protein or molecule selectively binds to phosphatidylinositol bisphosphate (PIP2), a key lipid in cell signaling.
What genes are involved in phosphatidylinositol bisphosphate binding?
Key genes include RAB35, STING1, ANXA2, TP53, and PTEN, among others.
How does phosphatidylinositol bisphosphate binding affect cell signaling?
It recruits effector proteins to membranes, triggering conformational changes and activating pathways such as AKT signaling and immune responses.
What diseases are associated with phosphatidylinositol bisphosphate binding?
Dysregulation is linked to cancer, autoinflammatory diseases, cataract formation, and neurological disorders.
What methods are used to study phosphatidylinositol bisphosphate binding?
Common methods include lipid binding assays, fluorescence microscopy, CRISPR knockout, and proteomics.
How can CRISPR be used to study phosphatidylinositol bisphosphate binding?
CRISPR knockout, point mutation, and knock-in models allow researchers to test the causal role of specific binding interactions in cells and organisms.
What is the role of PIP2 in migrasome formation?
The PIP2-Rab35 axis is essential for migrasome formation, as Rab35 binding to PIP2 drives the assembly of these structures.
How does STING bind to phosphoinositides?
STING binds to phosphoinositides like PIP2 through its transmembrane domain, which is required for its activation in innate immunity.
Can phosphatidylinositol bisphosphate binding be targeted therapeutically?
Yes, small molecules like neomycin can disrupt PIP2 binding, and targeting these interactions is being explored for cancer and immune disorders.
What is the connection between p53 and phosphatidylinositol bisphosphate binding?
p53 forms a nuclear signalosome with PIP2 to regulate AKT activation, linking lipid signaling to tumor suppression.
Conclusion
Phosphatidylinositol bisphosphate binding (GO:1902936) is a fundamental molecular function that orchestrates diverse cellular processes, from migrasome formation to immune signaling and nuclear AKT activation. Its dysregulation contributes to cancer, immune disorders, and eye diseases. Advances in CRISPR-based models and lipid biochemistry are providing unprecedented insights into the mechanisms and therapeutic potential of this interaction. Continued research will likely uncover new roles and targets for intervention.
References
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- 2. Li J et al.. 2026. Regulation of STING activation by phosphoinositide and cholesterol.. Nature 652(8109):499-507 PMID: 41639452
- 3. Drücker P et al.. 2014. Cooperative binding of annexin A2 to cholesterol- and phosphatidylinositol-4,5-bisphosphate-containing bilayers.. Biophys J 107(9):2070-81 PMID: 25418092
- 4. Chen M et al.. 2022. A p53-phosphoinositide signalosome regulates nuclear AKT activation.. Nat Cell Biol 24(7):1099-1113 PMID: 35798843
- 5. Gabev E et al.. 1989. Binding of neomycin to phosphatidylinositol 4,5-bisphosphate (PIP2).. Biochim Biophys Acta 979(1):105-12 PMID: 2537103
- 6. Muranaka Y et al.. 2024. Novel phosphatidylinositol flippases contribute to phosphoinositide homeostasis in the plasma membrane.. Biochem J 481(18):1187-1202 PMID: 39258799
- 7. Gulluni F et al.. 2021. PI(3,4)P2-mediated cytokinetic abscission prevents early senescence and cataract formation.. Science 374(6573):eabk0410 PMID: 34882480
- 8. Weeds A et al.. 1993. F-actin capping proteins.. Curr Opin Cell Biol 5(1):63-9 PMID: 8383512
