GO:0010314 phosphatidylinositol-5-phosphate binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0010314 phosphatidylinositol-5-phosphate binding describes the molecular function of selectively binding phosphatidylinositol-5-phosphate (PI5P), a low-abundance phosphoinositide phosphorylated at the 5' position of the inositol ring.
• PI5P-binding proteins include lipid kinases such as PI5P4Kγ (PIP4K2C), scaffolds such as Tom1, and guanine nucleotide exchange factors such as Tiam1 [1,5,6].
• PI5P binding can alter protein localization, stability, and catalytic activity, as shown for Tom1 VHS domain destabilization and Tiam1 activation during invasion [5,6].
• Systematic yeast proteome microarray screening has identified a broad set of PI5P-interacting proteins, indicating that PI5P binding is a widespread regulatory mechanism.
• PI5P4Kγ accumulates at the spindle pole and prevents microtubule depolymerization, linking PI5P metabolism to mitotic regulation.
• Genetic studies have associated phosphoinositide pathway genes with lacunar stroke, highlighting the biomedical relevance of PI5P-binding proteins.
Description
Phosphatidylinositol-5-phosphate (PI5P) is a minor phosphoinositide generated by phosphorylation of phosphatidylinositol at the 5' position of the inositol ring. The Gene Ontology term GO:0010314, phosphatidylinositol-5-phosphate binding, defines the molecular function of selectively recognizing this lipid. Unlike the more abundant phosphatidylinositol-4,5-bisphosphate, PI5P is present at low levels and is thought to act as a signaling lipid that recruits and regulates specific effector proteins. Understanding which proteins bind PI5P, and how this binding changes their behavior, is therefore central to phosphoinositide biology. Proteins that bind PI5P include lipid kinases, membrane trafficking adaptors, and cytoskeletal regulators. For example, the phosphatidylinositol 5-phosphate 4-kinase γ (PI5P4Kγ, gene PIP4K2C) is a lipid kinase that phosphorylates PI5P to phosphatidylinositol-4,5-bisphosphate, and its own regulation is linked to PI5P availability. The VHS domain of Tom1 preferentially binds PI5P and undergoes structural destabilization upon binding, suggesting that PI5P can act as a conformational switch. Tiam1, a Rac1 guanine nucleotide exchange factor, is activated by direct PI5P binding and promotes cell invasion. These examples illustrate that PI5P binding is not a passive interaction but a functional event that can change protein activity and localization. For researchers, GO:0010314 provides a precise annotation for experiments that measure lipid-protein interactions. The term is relevant to studies of membrane trafficking, cytoskeletal dynamics, cell invasion, and mitosis [2,5,6]. Because PI5P is a low-abundance lipid, detecting specific binding requires sensitive methods such as lipid overlays, proteome microarrays, and recombinant protein binding assays. This article summarizes the definition, mechanisms, key genes, disease links, and experimental models for studying phosphatidylinositol-5-phosphate binding.
phosphatidylinositol-5-phosphate binding At A Glance
| GO ID | GO:0010314 |
|---|---|
| GO term | phosphatidylinositol-5-phosphate binding |
| Ontology | molecular_function |
| Synonym | none listed in QuickGO |
| Definition | Binding to phosphatidylinositol-5-phosphate, a derivative of phosphatidylinositol in which the inositol ring is phosphorylated at the 5' position. |
| Major function | Selective recognition of PI5P by proteins, affecting localization, stability, or activity |
| Example binders | PI5P4Kγ (PIP4K2C), Tom1, Tiam1, and other proteins identified by proteome microarrays [1,4,5,6] |
| Related lipid | Phosphatidylinositol-5-phosphate (PI5P), a low-abundance phosphoinositide |
| Research methods | Lipid overlay assays, yeast proteome microarrays, recombinant protein binding, structural studies [4,5] |
What Is GO:0010314?
GO:0010314 phosphatidylinositol-5-phosphate binding is a molecular function term defined as binding to phosphatidylinositol-5-phosphate, a derivative of phosphatidylinositol in which the inositol ring is phosphorylated at the 5' position. In practical terms, it describes the ability of a protein or protein domain to selectively interact with PI5P, often through a lipid-binding pocket or electrostatic surface. This binding can be measured biochemically and can influence protein localization, stability, or enzymatic activity [4,5,6].
Why Is phosphatidylinositol-5-phosphate binding Important in Cell Biology?
GO:0010314 is important because PI5P is a low-abundance signaling lipid that can exert disproportionate effects on cell behavior through selective protein binding. Proteins that bind PI5P participate in membrane trafficking, cytoskeletal regulation, cell invasion, and mitosis [2,5,6]. Systematic screening has revealed that many proteins interact with PI5P, suggesting that this lipid is a broad regulatory node rather than a rare curiosity. Moreover, genetic variation in phosphoinositide pathway genes has been associated with lacunar stroke, underscoring the clinical relevance of PI5P-binding proteins. For researchers, annotating a protein with GO:0010314 provides a precise functional label that can guide mechanistic experiments and drug discovery efforts.
• PI5P is a low-abundance phosphoinositide, and its binding proteins are key effectors of lipid signaling.
• PI5P binding can destabilize protein domains, as shown for the Tom1 VHS domain, acting as a conformational switch.
• Tiam1 activation by PI5P promotes cell invasion, linking PI5P binding to cancer-related phenotypes.
• PI5P4Kγ accumulates at the spindle pole and prevents microtubule depolymerization, connecting PI5P metabolism to mitosis.
• Yeast proteome microarrays have identified many PI5P-interacting proteins, indicating broad functional relevance.
• PI5P4Kγ is a target of chemical probes, suggesting that PI5P-binding proteins are druggable.
• Genetic studies have associated phosphoinositide pathway genes with lacunar stroke, a common stroke subtype.
• PI5P4Kα (PIP4K2A) has conserved RNA-binding activity, expanding the functional repertoire of PI5P-related proteins.
• Understanding PI5P binding can inform studies of membrane trafficking and cytoskeletal dynamics [5,6].
• GO:0010314 provides a standardized annotation for lipid-protein interaction experiments.
Molecular Mechanism of phosphatidylinositol-5-phosphate binding
Lipid recognition and binding pocket
In simple terms: Proteins that bind PI5P have a pocket or surface that fits this specific lipid.
PI5P-binding proteins recognize the 5' phosphate of the inositol ring, which distinguishes PI5P from other phosphoinositides. The VHS domain of Tom1 preferentially binds PI5P, and this interaction destabilizes the domain structure, suggesting that the binding site is coupled to conformational change. Systematic analysis using yeast proteome microarrays has identified numerous PI5P-interacting proteins, indicating that diverse structural folds can support PI5P binding.
Conformational and stability effects
In simple terms: Binding to PI5P can change the shape or stability of a protein.
For Tom1, preferential PI5P binding contributes to destabilization of the VHS domain structure, which may regulate its function in membrane trafficking. This suggests that PI5P can act as an allosteric regulator rather than a simple membrane anchor. Such conformational effects are likely to influence protein-protein interactions and downstream signaling.
Enzymatic and signaling regulation
In simple terms: PI5P binding can turn enzymes or signaling proteins on or off.
Tiam1, a Rac1 guanine nucleotide exchange factor, is activated by direct PI5P binding, which promotes cell invasion. PI5P4Kγ is a lipid kinase that phosphorylates PI5P, and its regulation is linked to PI5P availability. These examples show that PI5P binding can directly modulate catalytic activity and downstream signaling pathways.
Subcellular localization and mitotic roles
In simple terms: PI5P-binding proteins can be targeted to specific cellular locations.
PI5P4Kγ accumulates at the spindle pole and prevents microtubule depolymerization, linking PI5P metabolism to mitotic spindle regulation. This localization suggests that PI5P-binding proteins can be recruited to specific structures to influence cytoskeletal dynamics. The mechanism likely involves both lipid binding and protein-protein interactions.
RNA-binding and non-canonical functions
In simple terms: Some PI5P-related proteins can also bind RNA.
PIP4K2A (PI5P4Kα) has conserved RNA-binding activity, indicating that PI5P-related proteins may have functions beyond lipid metabolism. This expands the potential roles of PI5P-binding proteins in RNA processing or translation. Researchers should consider these non-canonical activities when interpreting experimental results.
Key Genes Involved in GO:0010314 phosphatidylinositol-5-phosphate binding
The following genes encode proteins that bind phosphatidylinositol-5-phosphate or are directly involved in its metabolism and signaling.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PIP4K2C | PI5P4Kγ lipid kinase that phosphorylates PI5P; accumulates at spindle pole [1,2] | Mitosis, microtubule dynamics, chemical probe target [2,7] |
| PIP4K2A | PI5P4Kα lipid kinase with conserved RNA-binding activity | RNA binding, lipid signaling crosstalk |
| TOM1 | VHS domain protein that preferentially binds PI5P; domain destabilization | Membrane trafficking, conformational regulation |
| TIAM1 | Rac1 GEF activated by PI5P binding; promotes invasion | Cancer invasion, cytoskeletal dynamics |
| PIP4K2B | PI5P 4-kinase family member | Lipid metabolism, potential PI5P binding |
| PIP5K1A | Phosphatidylinositol-4-phosphate 5-kinase | PI5P-related phosphoinositide synthesis |
| PIP5K1B | Phosphatidylinositol-4-phosphate 5-kinase | Phosphoinositide signaling |
| PIP5K1C | Phosphatidylinositol-4-phosphate 5-kinase | Phosphoinositide signaling |
| MTM1 | Myotubularin lipid phosphatase | PI5P dephosphorylation, membrane trafficking |
| MTMR2 | Myotubularin-related phosphatase | Phosphoinositide turnover |
| OCRL | Inositol polyphosphate 5-phosphatase | PI5P metabolism, Lowe syndrome |
| INPP5B | Inositol polyphosphate 5-phosphatase | Phosphoinositide signaling |
| SAC1 | Phosphoinositide phosphatase | PI5P regulation |
| VPS34 | PI3K class III | Phosphoinositide synthesis |
| PIK3C2A | PI3K class II alpha | Phosphoinositide signaling |
| PIK3C2B | PI3K class II beta | Phosphoinositide signaling |
| PIK3C3 | PI3K class III | Autophagy, phosphoinositide signaling |
| FIG4 | Phosphoinositide 5-phosphatase | PI5P metabolism, neurodegeneration |
How Is phosphatidylinositol-5-phosphate binding Regulated?
PI5P levels and binding are regulated by the balance of lipid kinases and phosphatases. PI5P4Kγ phosphorylates PI5P to generate phosphatidylinositol-4,5-bisphosphate, thereby reducing PI5P availability. Myotubularin phosphatases can dephosphorylate PI5P, further controlling its abundance. The localization of PI5P4Kγ to the spindle pole suggests cell-cycle-dependent regulation. Chemical probes targeting PI5P4Kγ have been identified, providing tools to modulate PI5P signaling. Additionally, PIP4K2A RNA-binding activity may represent a separate regulatory layer.
phosphatidylinositol-5-phosphate binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| TIAM1 | Cancer invasion and metastasis | Knockout and point-mutation cell lines; invasion assays |
| PIP4K2C | Mitotic regulation; cancer [1,2] | Knockout and overexpression models; spindle analysis |
| PIP4K2A | RNA binding; potential cancer role | Knockout and RNA-binding mutants |
| TOM1 | Membrane trafficking; neurodegeneration | Knockout and VHS domain mutants |
| FIG4 | Neurodegeneration; phosphoinositide metabolism | Knockout and point-mutation models |
Cancer and cell invasion
PI5P binding to Tiam1 activates Rac1 signaling and promotes cell invasion, a key step in cancer metastasis. This suggests that PI5P-binding proteins could be therapeutic targets in invasive cancers. PI5P4Kγ, which regulates PI5P levels, is also a potential drug target, and chemical probes have been developed.
Lacunar stroke
Genetic studies have associated phosphoinositide pathway genes with lacunar stroke, a common subtype of ischemic stroke. Although the exact mechanisms remain to be defined, these findings highlight the clinical relevance of PI5P-related signaling. Further research on PI5P-binding proteins may reveal new risk pathways.
Neurodegeneration and membrane trafficking
Phosphoinositide phosphatases such as FIG4 and MTM1 are linked to neurodegenerative and neuromuscular disorders. While direct evidence for PI5P binding in these diseases is limited, the broader phosphoinositide pathway is clearly important. Tom1, a PI5P-binding protein, functions in membrane trafficking, which is often disrupted in neurodegeneration.
From phosphatidylinositol-5-phosphate binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of PI5P binding affect cell invasion? | TIAM1 knockout and point-mutation cell lines |
| How does PI5P binding regulate spindle assembly? | PIP4K2C knockout and tagged knock-in |
| Does PI5P binding destabilize Tom1 VHS domain? | TOM1 point mutations in VHS domain |
| What proteins bind PI5P in a proteome-wide manner? | Yeast proteome microarrays |
| Can PI5P4Kγ be targeted by chemical probes? | Overexpression and inhibitor-treated cells |
| Does PIP4K2A RNA binding affect translation? | PIP4K2A knockout and RNA-binding mutants |
How to Study the phosphatidylinositol-5-phosphate binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Lipid overlay assay | Direct protein-lipid binding | Validate PI5P binding of candidate proteins |
| Yeast proteome microarray | Systematic protein-lipid interactions | Discover novel PI5P binders |
| NMR spectroscopy | Structural changes upon lipid binding | Study Tom1 VHS domain destabilization |
| Fluorescence microscopy | Subcellular localization | Visualize PI5P4Kγ at spindle pole |
| Invasion assay | Cell invasion capacity | Assess Tiam1 activation by PI5P |
| RNA-binding assay | Protein-RNA interaction | Study PIP4K2A RNA binding |
| Chemical probe treatment | Inhibition of PI5P4Kγ | Evaluate lipid kinase function |
Lipid overlay and binding assays
Lipid overlay assays using immobilized phosphoinositides can detect direct binding of recombinant proteins to PI5P. These assays are useful for validating candidate PI5P-binding proteins identified by screening. They can be combined with mutagenesis to map binding sites.
Proteome microarrays
Yeast proteome microarrays have been used to systematically identify PI5P-interacting proteins, revealing a broad set of binders. This approach enables unbiased discovery of novel PI5P-binding proteins and can be adapted to other organisms.
Structural and biophysical methods
Nuclear magnetic resonance and crystallography can reveal how proteins such as the Tom1 VHS domain bind PI5P and undergo conformational changes. These methods provide atomic-level insight into lipid recognition.
Cell-based imaging and functional assays
Fluorescence microscopy can visualize the localization of PI5P-binding proteins such as PI5P4Kγ at the spindle pole. Functional assays, such as invasion assays for Tiam1, link binding to cellular phenotypes.
How CRISPR Can Be Used to Study GO:0010314 phosphatidylinositol-5-phosphate binding
Knockout
CRISPR knockout of genes encoding PI5P-binding proteins, such as PIP4K2C or TIAM1, can reveal their roles in mitosis and invasion [2,6]. Knockout cell lines provide a clean background for rescue experiments with wild-type or binding-deficient mutants.
Point Mutation
Point mutations that abolish PI5P binding, for example in the Tom1 VHS domain, can test whether lipid binding is required for function. Such mutants are valuable for separating binding-dependent from binding-independent activities.
Knock-in
Knock-in of tagged versions of PI5P-binding proteins, such as GFP-PIP4K2C, allows visualization of their localization at the spindle pole. Tagged knock-ins preserve endogenous regulation and can be used for live-cell imaging.
Overexpression
Overexpression of PI5P-binding proteins or their mutants can amplify phenotypes and facilitate biochemical purification. For example, overexpression of Tiam1 can enhance invasion in a PI5P-dependent manner.
How EDITGENE Supports phosphatidylinositol-5-phosphate binding Research
Researchers studying phosphatidylinositol-5-phosphate binding-related genes often need to determine whether a candidate gene is causally involved in a specific cellular process or disease. CRISPR-based models provide a rigorous way to test causality by deleting, mutating, or tagging the gene of interest.
Contact EDITGENE today to design your custom CRISPR model for phosphatidylinositol-5-phosphate binding research.
Frequently Asked Questions About phosphatidylinositol-5-phosphate binding
What is phosphatidylinositol-5-phosphate binding?
It is the molecular function of selectively binding phosphatidylinositol-5-phosphate (PI5P), a low-abundance phosphoinositide, as defined by GO:0010314.
What genes are involved in phosphatidylinositol-5-phosphate binding?
Genes include PIP4K2C (PI5P4Kγ), PIP4K2A, TOM1, and TIAM1, among others identified by proteome microarrays [1,3,4,5,6].
How is phosphatidylinositol-5-phosphate binding studied?
Common methods include lipid overlay assays, yeast proteome microarrays, NMR spectroscopy, and cell-based imaging [2,4,5].
What is the role of PI5P4Kγ in mitosis?
PI5P4Kγ accumulates at the spindle pole and prevents microtubule depolymerization, linking PI5P metabolism to mitotic regulation.
Does PI5P binding affect cell invasion?
Yes, PI5P binding activates Tiam1, a Rac1 GEF, which promotes cell invasion.
Can PI5P binding change protein structure?
Yes, preferential PI5P binding destabilizes the VHS domain of Tom1, acting as a conformational switch.
Is phosphatidylinositol-5-phosphate binding linked to disease?
It has been linked to cancer invasion through Tiam1 and to lacunar stroke through phosphoinositide pathway genes [6,8].
What is the GO ID for phosphatidylinositol-5-phosphate binding?
The GO ID is GO:0010314.
Are there chemical probes for PI5P-binding proteins?
Yes, a chemical probe for PI5P4Kγ has been identified, providing a tool to modulate PI5P signaling.
Can CRISPR be used to study phosphatidylinositol-5-phosphate binding?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models can test the function of PI5P-binding proteins [2,5,6].
Conclusion
GO:0010314 phosphatidylinositol-5-phosphate binding defines a molecular function that is central to phosphoinositide signaling. Proteins such as PI5P4Kγ, Tom1, and Tiam1 use PI5P binding to regulate mitosis, membrane trafficking, and cell invasion [2,5,6]. Systematic screening has revealed that many proteins interact with PI5P, suggesting broad biological importance. Disease links, including cancer invasion and lacunar stroke, underscore the clinical relevance of this function [6,8]. CRISPR-based models and biochemical assays provide robust tools to dissect the mechanisms and therapeutic potential of PI5P-binding proteins.
References
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- 2. Lin TC et al.. 2019. Phosphatidylinositol-5-phosphate 4-kinase gamma accumulates at the spindle pole and prevents microtubule depolymerization.. Cell Div 14:9 PMID: 31452676
- 3. Behari J et al.. 2021. Conserved RNA Binding Activity of Phosphatidyl Inositol 5-Phosphate 4-Kinase (PIP4K2A).. Front Mol Biosci 8:631281 PMID: 34124142
- 4. Herianto S et al.. 2021. Systematic Analysis of Phosphatidylinositol-5-phosphate-Interacting Proteins Using Yeast Proteome Microarrays.. Anal Chem 93(2):868-877 PMID: 33302626
- 5. Xiong W et al.. 2019. Preferential phosphatidylinositol 5-phosphate binding contributes to a destabilization of the VHS domain structure of Tom1.. Sci Rep 9(1):10868 PMID: 31350523
- 6. Viaud J et al.. 2014. Phosphatidylinositol 5-phosphate regulates invasion through binding and activation of Tiam1.. Nat Commun 5:4080 PMID: 24905281
- 7. Drewry DH et al.. 2023. Identification of a chemical probe for lipid kinase phosphatidylinositol-5-phosphate 4-kinase gamma (PI5P4Kγ).. Curr Res Chem Biol 3 PMID: 41937984
- 8. Traylor M et al.. 2021. Genetic basis of lacunar stroke: a pooled analysis of individual patient data and genome-wide association studies.. Lancet Neurol 20(5):351-361 PMID: 33773637
