GO:0051721 protein phosphatase 2A binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0051721 (protein phosphatase 2A binding) is a molecular function describing the selective interaction of a protein with the PP2A holoenzyme or its subunits.
• PP2A binding proteins act as substrate adaptors, regulators, or targeting subunits that determine where and when PP2A dephosphorylates its targets.
• This binding function controls diverse processes including DNA replication, mitosis, telomere capping, Wnt signaling, angiogenesis, and viral transcription.
• Dysregulated PP2A binding contributes to cancer, neurodegeneration, metabolic disorders, and susceptibility to viral infection.
• CRISPR knockout, point mutation, knock-in, and overexpression models are essential to dissect the causal role of PP2A-binding proteins.
• EDITGENE provides end-to-end CRISPR cell model and screening services to study PP2A-binding proteins in disease and drug response.
Description
Protein phosphatase 2A (PP2A) is a major serine/threonine phosphatase that regulates a vast array of cellular signaling events. The Gene Ontology molecular function term GO:0051721, protein phosphatase 2A binding, describes the physical interaction between a protein and PP2A, including its catalytic and regulatory subunits. This binding event is not merely a passive association; it often dictates substrate specificity, subcellular localization, and catalytic activity of the phosphatase. Researchers study GO:0051721 to understand how PP2A is recruited to specific substrates and how this recruitment is altered in disease. For example, binding of PP2A to CDC45 controls DNA replication origin firing, while its interaction with hnRNPA1 regulates telomere capping during mitosis. In the context of viral infection, PP2A binding to Marburg virus proteins is required for efficient viral transcription. Thus, GO:0051721 is a central node linking phosphatase regulation to fundamental cell biology and human disease. Understanding the proteins that mediate PP2A binding, and the consequences of disrupting these interactions, is critical for developing targeted therapies.
protein phosphatase 2A binding At A Glance
| GO ID | GO:0051721 |
|---|---|
| GO term | protein phosphatase 2A binding |
| Ontology | molecular_function |
| Synonym | protein phosphatase 2 binding |
| Major function | Binding to protein phosphatase 2A, often regulating its activity, substrate targeting, or localization |
| Related processes | DNA replication, mitosis, telomere maintenance, Wnt signaling, angiogenesis, viral transcription |
| Example binding proteins | CDC45, hnRNPA1, AHR, flotillin-1, casein kinase 1α, Marburg virus VP30 |
| Disease relevance | Cancer, neurodegeneration, metabolic disorders, viral infections |
| Research methods | Co-immunoprecipitation, GST pull-down, CRISPR knockout, point mutation, knock-in, overexpression |
What Is GO:0051721?
GO:0051721 (protein phosphatase 2A binding) is defined as the selective and non-covalent interaction of a protein with protein phosphatase 2A (PP2A). This molecular function encompasses binding to the PP2A holoenzyme, which typically consists of a catalytic C subunit, a scaffold A subunit, and a variable regulatory B subunit. Proteins annotated with this term may act as substrate adaptors, regulatory subunits, or targeting proteins that modulate PP2A activity, localization, or substrate specificity.
Why Is protein phosphatase 2A binding Important in Cell Biology?
Protein phosphatase 2A binding is a fundamental molecular function that determines how PP2A, one of the most abundant phosphatases in eukaryotic cells, is directed to its substrates. Because PP2A regulates key signaling pathways such as Wnt, AKT, and MAPK, proteins that bind PP2A can act as critical modulators of cell proliferation, survival, and differentiation. Disruption of these interactions is implicated in cancer, where PP2A acts as a tumor suppressor, and in viral infections, where viruses hijack PP2A binding to promote their replication. Therefore, studying GO:0051721 provides mechanistic insights into disease and identifies potential therapeutic targets.
• Controls DNA replication by targeting PP2A to CDC45, ensuring proper origin firing.
• Regulates mitotic telomere capping through hnRNPA1 dephosphorylation and TERRA formation.
• Modulates Wnt signaling by affecting casein kinase 1α interaction with PP2A.
• Influences angiogenesis via flotillin-1 dephosphorylation and endothelial cell migration.
• Affects drug resistance and cytotoxicity by dephosphorylating AHR and MDR1.
• Plays a role in Alzheimer's disease-related Aβ protein expression and stability.
• Is a crucial host factor for Marburg virus transcription.
• Contributes to benzodiazepine dependence, with PP2A inhibitors as potential pharmacotherapy.
• Serves as a target for cancer therapy due to PP2A's tumor suppressor function.
• Provides a molecular handle for CRISPR-based functional studies of PP2A regulation.
Molecular Mechanism of protein phosphatase 2A binding
Substrate Recognition and Adaptor Function
In simple terms: Binding proteins act like adaptors that bring PP2A close to its target proteins.
Many proteins that bind PP2A function as substrate adaptors or regulatory subunits. For example, CDC45 binds PP2A to regulate DNA replication, and this interaction is essential for controlling ongoing replication. Similarly, hnRNPA1 binding to PP2A mediates its dephosphorylation during mitosis, which is required for telomere capping. These interactions often involve the B regulatory subunits of PP2A, which dictate substrate specificity.
Regulation of PP2A Catalytic Activity
In simple terms: Some binding partners switch PP2A activity on or off.
Binding of certain proteins can directly modulate PP2A catalytic activity. For instance, casein kinase 1α interaction with PP2A is modulated by Wnt signaling, affecting downstream phosphorylation events. In the context of drug resistance, PP2A binding to AHR and MDR1 leads to their dephosphorylation, altering their function. These examples illustrate that PP2A binding is not just targeting but also a means of regulating phosphatase activity.
Subcellular Localization and Scaffolding
In simple terms: Binding proteins can anchor PP2A to specific parts of the cell.
PP2A binding proteins often contain scaffolding domains that localize the phosphatase to specific subcellular compartments. Flotillin-1 dephosphorylation by PP2A up-regulates endothelial cell migration and angiogenesis, suggesting that binding occurs at membrane microdomains. Similarly, PP2A Aα regulates Aβ protein expression and stability, possibly through interactions in specific cellular compartments.
Viral Hijacking of PP2A Binding
In simple terms: Viruses can use PP2A binding to their own advantage.
The cellular PP2A is a crucial host factor for Marburg virus transcription, and viral proteins likely bind PP2A to facilitate this process. This highlights how pathogens can exploit GO:0051721 for their replication. Understanding these interactions may lead to antiviral strategies.
Pharmacological Modulation of PP2A Binding
In simple terms: Drugs can interfere with PP2A binding to treat conditions like benzodiazepine dependence.
PP2A inhibitors have been proposed as a possible pharmacotherapy for benzodiazepine dependence, indicating that modulating PP2A binding or activity can have therapeutic effects. This suggests that small molecules targeting PP2A interactions could be developed for various diseases.
Key Genes Involved in GO:0051721 protein phosphatase 2A binding
The following genes encode proteins that bind PP2A and are central to the functions of GO:0051721.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CDC45 | Binds PP2A to regulate DNA replication origin firing | Studied for replication stress and cancer |
| HNRNPA1 | Binds PP2A for mitotic dephosphorylation and telomere capping | Implicated in telomere maintenance and cancer |
| AHR | Binds PP2A, leading to dephosphorylation and altered drug resistance | Model for xenobiotic response and chemoresistance |
| MDR1 | Binds PP2A, affecting drug efflux and resistance | Target for overcoming multidrug resistance |
| FLOT1 | Binds PP2A, dephosphorylation up-regulates angiogenesis | Studied in endothelial cell migration |
| CSNK1A1 | Interacts with PP2A, modulated by Wnt signaling | Key in Wnt pathway and cancer |
| PPP2CA | Catalytic subunit of PP2A, binds regulatory proteins | Core component of PP2A holoenzyme |
| PPP2R1A | Scaffold A subunit of PP2A, mediates binding | Mutations found in cancer |
| PPP2R2A | B regulatory subunit, targets PP2A to substrates | Determines substrate specificity |
| PPP2R5A | B' regulatory subunit, binds PP2A | Regulates PP2A activity |
| APP | Amyloid precursor protein, regulated by PP2A Aα | Alzheimer's disease research |
| MAPT | Tau protein, dephosphorylated by PP2A | Neurodegeneration |
| AKT1 | Signaling kinase regulated by PP2A | Cancer and metabolism |
| CTNNB1 | Beta-catenin, affected by PP2A via CK1α | Wnt signaling and cancer |
| TERRA | Telomeric repeat-containing RNA, regulated by hnRNPA1-PP2A | Telomere biology |
| VP30 | Marburg virus protein, interacts with PP2A | Viral transcription |
| GABAA receptor | Modulated by PP2A in benzodiazepine dependence | Addiction research |
How Is protein phosphatase 2A binding Regulated?
PP2A binding is regulated at multiple levels. The expression and post-translational modification of PP2A subunits and their binding partners can alter interaction affinities. For example, Wnt signaling modulates the interaction between casein kinase 1α and PP2A. Phosphorylation of PP2A regulatory subunits can affect binding to substrates. Additionally, viral proteins can hijack PP2A binding to promote their own transcription. Small molecule inhibitors can also modulate PP2A activity and binding.
protein phosphatase 2A binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| AHR | Drug resistance in cancer | Knockout of AHR or PP2A subunits in cancer cell lines |
| MDR1 | Multidrug resistance | Overexpression of MDR1 with PP2A binding mutants |
| APP | Alzheimer's disease | Knock-in of APP mutations in neuronal cells |
| MAPT | Tauopathy | Point mutation of tau phosphorylation sites |
| VP30 | Marburg virus infection | Knockout of PP2A in viral infection models |
Cancer
PP2A is a tumor suppressor, and proteins that bind PP2A can influence cancer development. For instance, PP2A-mediated dephosphorylation of AHR and MDR1 affects drug resistance and cytotoxicity in cancer cells. Mutations in PP2A subunits are found in various cancers, and targeting PP2A binding interactions is a potential therapeutic strategy.
Neurodegeneration
PP2A Aα regulates Aβ protein expression and stability, linking PP2A binding to Alzheimer's disease pathology. Tau hyperphosphorylation, a hallmark of neurodegeneration, is counteracted by PP2A, and disruption of PP2A binding may contribute to disease.
Viral Infections
Marburg virus requires cellular PP2A for efficient transcription, and viral proteins likely bind PP2A to facilitate this process. This highlights PP2A binding as a potential antiviral target.
Addiction
PP2A inhibitors show promise for benzodiazepine dependence, suggesting that PP2A binding and activity are involved in addiction pathways.
From protein phosphatase 2A binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of PP2A binding affect DNA replication? | CRISPR knockout of CDC45 binding domain |
| How does PP2A binding regulate telomere capping? | Point mutation of hnRNPA1 phosphorylation sites |
| Can PP2A binding be targeted for cancer therapy? | Knock-in of PP2A subunit mutations |
| What is the role of PP2A binding in viral transcription? | Overexpression of viral proteins in PP2A-knockout cells |
| Does PP2A binding modulate Wnt signaling? | Knockout of CSNK1A1 in Wnt reporter cells |
| How does PP2A binding affect angiogenesis? | Endothelial cell knockout of FLOT1 |
How to Study the protein phosphatase 2A binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Co-immunoprecipitation | Physical interaction between PP2A and target | Confirm binding in cells |
| GST pull-down | Direct binding in vitro | Map interaction domains |
| CRISPR knockout | Loss-of-function effects | Test necessity of binding |
| Phosphoproteomics | Global phosphorylation changes | Identify downstream targets |
| Live-cell imaging | Subcellular localization and dynamics | Study spatial regulation |
| RNA-seq | Transcriptional changes | Assess pathway effects |
| Viral infection assays | Viral replication | Test host factor requirement |
| Drug sensitivity assays | Cell viability and resistance | Evaluate therapeutic potential |
Co-immunoprecipitation and Pull-down
Co-immunoprecipitation (co-IP) and GST pull-down assays are standard methods to detect physical interactions between PP2A and candidate binding proteins. These techniques can confirm GO:0051721 annotations and map interaction domains.
CRISPR-Based Functional Genomics
CRISPR knockout, point mutation, and knock-in models allow researchers to test the causal role of specific PP2A binding interfaces. For example, knocking out the PP2A-binding domain of CDC45 can reveal its importance in DNA replication.
Phosphoproteomics
Mass spectrometry-based phosphoproteomics can identify changes in phosphorylation upon disruption of PP2A binding, providing global insights into downstream signaling.
Live-Cell Imaging
Fluorescence microscopy of tagged PP2A subunits and binding proteins can visualize their co-localization and dynamics in real time, shedding light on spatial regulation.
How CRISPR Can Be Used to Study GO:0051721 protein phosphatase 2A binding
Knockout
CRISPR knockout of genes encoding PP2A-binding proteins can abolish specific interactions and reveal their cellular functions. For example, knocking out CDC45 or its PP2A-binding domain impairs DNA replication.
Point Mutation
Introducing point mutations in the binding interface of PP2A or its partners can selectively disrupt the interaction without affecting other functions. This is useful for studying phosphorylation site mutants of hnRNPA1.
Knock-in
Knock-in of tagged or mutant versions of PP2A subunits allows for precise tracking and functional analysis. For instance, knock-in of a PP2A Aα mutant can model cancer-associated mutations.
Overexpression
Overexpression of PP2A-binding proteins can amplify the interaction and downstream effects, useful for studying viral hijacking or drug resistance.
How EDITGENE Supports protein phosphatase 2A binding Research
Researchers studying protein phosphatase 2A binding-related genes often need to determine whether a candidate gene is causally involved in a specific cellular process or disease. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this discovery, from knockout to precise point mutations and library screening.
Contact EDITGENE today to design your custom CRISPR model for protein phosphatase 2A binding research.
Frequently Asked Questions About protein phosphatase 2A binding
What is GO:0051721?
GO:0051721 is the Gene Ontology molecular function term for protein phosphatase 2A binding, describing the interaction of a protein with PP2A.
What genes are involved in protein phosphatase 2A binding?
Genes include CDC45, HNRNPA1, AHR, MDR1, FLOT1, CSNK1A1, and PP2A subunit genes such as PPP2CA and PPP2R1A.
How does protein phosphatase 2A binding regulate DNA replication?
CDC45 binds PP2A to control ongoing DNA replication, and disruption of this interaction impairs replication.
Is protein phosphatase 2A binding involved in cancer?
Yes, PP2A is a tumor suppressor, and binding proteins such as AHR and MDR1 affect drug resistance and cytotoxicity.
What diseases are linked to protein phosphatase 2A binding?
Cancer, Alzheimer's disease, viral infections like Marburg, and benzodiazepine dependence.
How can I study protein phosphatase 2A binding?
Use co-immunoprecipitation, CRISPR knockout, point mutation, knock-in, overexpression, and phosphoproteomics.
What are the regulatory subunits of PP2A?
PP2A holoenzyme includes A scaffold, C catalytic, and B regulatory subunits; B subunits determine substrate specificity.
Does protein phosphatase 2A binding affect Wnt signaling?
Yes, Wnt signaling modulates the interaction between casein kinase 1α and PP2A, affecting downstream events.
Can PP2A binding be targeted therapeutically?
PP2A inhibitors are being explored for benzodiazepine dependence, and targeting PP2A interactions is a strategy in cancer.
What CRISPR models are available for PP2A binding research?
EDITGENE offers knockout, point mutation, knock-in, overexpression, and library screening services for PP2A-binding genes.
Conclusion
GO:0051721 (protein phosphatase 2A binding) is a critical molecular function that governs PP2A substrate specificity and activity. Its roles span DNA replication, mitosis, signaling, and viral infection, with broad implications for cancer, neurodegeneration, and infectious diseases. Continued research using CRISPR models and advanced proteomics will unravel the precise mechanisms and therapeutic potential of PP2A binding proteins.
References
- 1. Kobayashi C et al.. 2025. Protein phosphatase 2A inhibitors: a possible pharmacotherapy for benzodiazepine dependence.. J Pharm Pharmacol 77(3):335-340 PMID: 39546584
- 2. O'Connor CM et al.. 2019. Protein phosphatase 2A Aα regulates Aβ protein expression and stability.. J Biol Chem 294(15):5923-5934 PMID: 30796164
- 3. Chen L et al.. 2022. Protein phosphatase 2A regulates cytotoxicity and drug resistance by dephosphorylating AHR and MDR1.. J Biol Chem 298(5):101918 PMID: 35405096
- 4. Thalwieser Z et al.. 2019. Protein phosphatase 2A-mediated flotillin-1 dephosphorylation up-regulates endothelial cell migration and angiogenesis regulation.. J Biol Chem 294(52):20196-20206 PMID: 31753918
- 5. Shen C et al.. 2025. Wnt signaling inhibits casein kinase 1α activity by modulating its interaction with protein phosphatase 2A.. Cell Rep 44(2):115274 PMID: 39908140
- 6. Sui JD et al.. 2022. Protein Phosphatase 2A-Dependent Mitotic hnRNPA1 Dephosphorylation and TERRA Formation Facilitate Telomere Capping.. Mol Cancer Res 20(4):583-595 PMID: 34933911
- 7. von Creytz I et al.. 2024. The cellular protein phosphatase 2A is a crucial host factor for Marburg virus transcription.. J Virol 98(9):e0104724 PMID: 39194238
- 8. Perl AL et al.. 2019. Protein phosphatase 2A controls ongoing DNA replication by binding to and regulating cell division cycle 45 (CDC45).. J Biol Chem 294(45):17043-17059 PMID: 31562245
