GO:2001145 negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:2001145 describes any process that stops, prevents, or reduces the activity of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase, the enzyme that removes the 5-phosphate from PIP3 to produce PI(3,4)P2.
• This regulatory term sits at the heart of PI3K/AKT signaling because it controls the abundance of PIP3, a key lipid second messenger.
• The 5-phosphatase family includes SHIP1, SHIP2, and SKIP, which are differentially expressed and regulate insulin signaling, glucose uptake, and immune cell function.
• Viral oncoproteins such as HTLV-1 Tax can down-regulate 5-phosphatase expression via NF-kappaB, linking this GO term to viral pathogenesis.
• SHIP2 inhibition alters redox-sensitive PI3K/AKT and MAPK signaling through PTEN over-activation in cervical cancer cells, showing crosstalk between 5-phosphatases and tumor suppressors.
• CRISPR knockout, point-mutation, knock-in, and overexpression models are essential to dissect how negative regulation of 5-phosphatase activity shapes cell signaling and disease.
Description
GO:2001145, negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity, is a biological process term that captures the cellular mechanisms which suppress the enzymatic removal of the 5-phosphate from phosphatidylinositol-3,4,5-trisphosphate (PIP3). PIP3 is a critical lipid second messenger generated by PI3K, and its levels are tightly controlled by opposing phosphatases, including the 5-phosphatases that convert PIP3 to phosphatidylinositol-3,4-bisphosphate (PI(3,4)P2). Because PIP3 governs AKT activation, glucose transport, and cell survival, understanding how 5-phosphatase activity is negatively regulated is fundamental to PI3K biology. Researchers study GO:2001145 to explain how cells fine-tune PIP3 signals in response to growth factors such as insulin, nerve growth factor, and epidermal growth factor. The 5-phosphatase family includes SHIP1, SHIP2, and SKIP, each with distinct tissue distribution and regulatory inputs. Negative regulation of these enzymes can occur through transcriptional repression, post-translational modification, or protein-protein interactions, and disruption of this control contributes to metabolic disease, immune dysfunction, and cancer. This article integrates the QuickGO definition with verified PubMed literature to provide a research-grade overview of GO:2001145, its molecular players, disease relevance, and the CRISPR-based methods used to interrogate it.
negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity At A Glance
| GO ID | GO:2001145 |
|---|---|
| GO term | negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity |
| Ontology | biological_process |
| Synonym | none |
| Major function | Suppression of 5-phosphatase-mediated PIP3 dephosphorylation, preserving PIP3 signaling |
| Target enzyme | Phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase (e.g., SHIP1, SHIP2, SKIP) |
| Substrate affected | Phosphatidylinositol-3,4,5-trisphosphate (PIP3) |
| Product of enzyme activity | Phosphatidylinositol-3,4-bisphosphate (PI(3,4)P2) |
| Related signaling pathway | PI3K/AKT signaling |
| Disease relevance | Cancer, insulin resistance, immune dysregulation, viral pathogenesis |
What Is GO:2001145?
GO:2001145 is defined by QuickGO as any process that stops, prevents, or reduces the frequency, rate, or extent of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity. In practical terms, it covers the cellular strategies that lower the ability of 5-phosphatase enzymes to dephosphorylate PIP3 at the 5-position, thereby preserving PIP3 pools and sustaining downstream PI3K/AKT signaling.
Why Is negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity Important in Cell Biology?
GO:2001145 is important because it defines a control point for PIP3 abundance, a lipid that dictates cell growth, survival, and metabolism. By negatively regulating 5-phosphatase activity, cells can sustain PIP3 signals that drive AKT activation and GLUT4 exocytosis in response to insulin. Conversely, loss of this negative regulation can contribute to pathological states such as cancer and metabolic disease. Understanding this term therefore informs therapeutic strategies targeting PI3K/AKT signaling and provides a framework for interpreting how viral proteins and oncogenes rewire lipid phosphatase networks.
• Controls PIP3 levels, a central node in PI3K/AKT signaling.
• Regulates insulin-stimulated glucose uptake via GLUT4 exocytosis in skeletal muscle.
• Modulates immune cell function through SHIP1 and SHIP2.
• Links to viral oncogenesis via HTLV-1 Tax-mediated down-regulation of 5-phosphatases.
• Influences redox-sensitive signaling and PTEN crosstalk in cancer cells.
• Impacts growth factor signaling downstream of NGF and EGF.
• Provides a mechanistic explanation for feedback control of lipid second messengers.
• Offers therapeutic targets for metabolic and proliferative diseases.
• Guides design of CRISPR models to test causality of 5-phosphatase regulators.
• Helps interpret bioinformatics data on PI3K pathway mutations.
What Happens During negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity?
Transcriptional suppression of 5-phosphatase genes
In simple terms: The cell makes fewer 5-phosphatase enzymes by turning down their genes.
Negative regulation of 5-phosphatase activity can begin at the transcriptional level. The HTLV-1 Tax protein down-regulates the expression of phosphatidylinositol 3,4,5-trisphosphate inositol phosphatases via the NF-kappaB pathway, reducing the amount of enzyme available to dephosphorylate PIP3. This transcriptional repression preserves PIP3 pools and sustains downstream signaling.
Post-translational inhibition of enzyme activity
In simple terms: Even if the enzyme is present, the cell can switch it off chemically.
Beyond transcription, 5-phosphatase activity can be reduced by post-translational modifications or interacting proteins that block catalysis. While specific modifications for SHIP2 and SKIP are still being mapped, the general principle is that negative regulation reduces the frequency or rate of PIP3 dephosphorylation without necessarily changing enzyme abundance. This layer of control allows rapid, reversible tuning of PIP3 signals.
Competition with PI3K and other PIP3 effectors
In simple terms: Other proteins can outcompete the 5-phosphatase for PIP3 or its binding partners.
Negative regulation can also occur indirectly when PI3K activity or PIP3 effector proteins outcompete 5-phosphatases for access to PIP3. For example, growth factor stimulation activates PI3K to generate PIP3 and recruits effectors such as GRP1 via its pleckstrin homology domain, which requires PI3K activation. This competition effectively reduces the fraction of PIP3 available for 5-phosphatase-mediated conversion to PI(3,4)P2.
Feedback loops involving PTEN and other phosphatases
In simple terms: Other phosphatases can indirectly change how much 5-phosphatase activity is needed.
SHIP2 inhibition alters redox-induced PI3K/AKT and MAP kinase pathways via PTEN over-activation in cervical cancer cells, illustrating that negative regulation of 5-phosphatase activity is embedded in a network of phosphatase crosstalk. When 5-phosphatase activity is reduced, PTEN may compensate by depleting PIP3, creating a feedback loop that shapes the net signaling outcome.
Physiological context: insulin signaling and GLUT4 exocytosis
In simple terms: In muscle, blocking the 5-phosphatase helps insulin move glucose transporters to the cell surface.
SKIP is a PIP3 5-phosphatase enriched in skeletal muscle and kidney, and its regulation directly impacts insulin signaling and GLUT4 exocytosis. Negative regulation of SKIP activity would be expected to elevate PIP3 and enhance insulin-stimulated glucose uptake, providing a physiological rationale for studying GO:2001145 in metabolic tissues.
Key Genes Involved in GO:2001145 negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity
The following genes and proteins are central to the negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity and its downstream biology.
| Gene | Major Role | Research Relevance |
|---|---|---|
| INPP5D (SHIP1) | 5-phosphatase that converts PIP3 to PI(3,4)P2 | Immune cell signaling and hematologic malignancies |
| INPPL1 (SHIP2) | 5-phosphatase regulating insulin sensitivity and cytoskeleton | Metabolic disease and cancer |
| SKIP (INPP5K) | Skeletal muscle and kidney enriched 5-phosphatase | Insulin signaling and GLUT4 exocytosis |
| PTEN | 3-phosphatase that depletes PIP3 | Tumor suppressor crosstalk with 5-phosphatases |
| PIK3CA | Catalytic subunit of PI3K generating PIP3 | Oncogenic driver opposing 5-phosphatase activity |
| PIK3R1 | Regulatory subunit of PI3K | Modulates PIP3 production and 5-phosphatase demand |
| AKT1 | Serine/threonine kinase activated by PIP3 | Readout of 5-phosphatase regulation |
| NFKB1 | Transcription factor mediating Tax-induced repression | Viral down-regulation of 5-phosphatases |
| RELA | NF-kappaB subunit involved in Tax signaling | Transcriptional control of 5-phosphatase genes |
| GRP1 (CYTH3) | PIP3-binding effector with pleckstrin homology domain | PIP3 sensing and membrane recruitment |
| SLC2A4 (GLUT4) | Insulin-responsive glucose transporter | Functional endpoint of SKIP regulation |
| INSR | Insulin receptor upstream of PI3K | Context for SKIP-mediated glucose uptake |
| IRS1 | Insulin receptor substrate 1 | Links insulin signaling to PI3K/PIP3 |
| TNF | Cytokine influencing SHIP2 and redox signaling | Inflammatory modulation of 5-phosphatase pathways |
| SRC | Kinase implicated in redox-sensitive signaling | Crosstalk with PI3K/MAPK |
| MAPK1 (ERK2) | MAP kinase downstream of redox and PI3K | Readout of SHIP2 inhibition |
| MAPK3 (ERK1) | MAP kinase downstream of redox and PI3K | Readout of SHIP2 inhibition |
| MIR155 | MicroRNA influencing cell-mediated immunity | Potential indirect regulator of immune signaling |
How Is negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity Regulated?
The negative regulation of 5-phosphatase activity is itself regulated at multiple levels. Transcriptionally, the HTLV-1 Tax protein represses 5-phosphatase gene expression through NF-kappaB, reducing enzyme availability. Post-translationally, redox state and kinase cascades can alter 5-phosphatase function; SHIP2 inhibition changes redox-induced PI3K/AKT and MAPK signaling via PTEN over-activation. In insulin-sensitive tissues, SKIP activity is tuned to match metabolic demand, and its regulation determines GLUT4 exocytosis. Additionally, growth factor signaling through NGF and EGF recruits PIP3 effectors such as GRP1, indirectly shaping the effective 5-phosphatase activity on PIP3. Together, these layers ensure that PIP3 signals are context-appropriate and reversible.
negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| INPPL1 (SHIP2) | Cervical cancer, redox signaling, insulin resistance | SHIP2 knockout or point-mutation in HeLa or C33A cells |
| INPP5K (SKIP) | Insulin resistance, glucose intolerance | SKIP knockout in skeletal muscle cells or mouse models |
| INPP5D (SHIP1) | Leukemia, immune dysregulation | SHIP1 knockout in hematopoietic cell lines |
| PTEN | Cancer, PTEN hamartoma tumor syndrome | PTEN knock-in or knockout with SHIP2 perturbation |
| HTLV-1 Tax | Adult T-cell leukemia/lymphoma | Tax-expressing T-cell lines with NF-kappaB inhibition |
Cancer and PI3K/AKT dysregulation
Altered negative regulation of 5-phosphatase activity can tip the balance toward PIP3 accumulation and constitutive AKT activation, a hallmark of many cancers. In cervical cancer cells, SHIP2 inhibition alters redox-induced PI3K/AKT and MAP kinase pathways via PTEN over-activation, demonstrating that 5-phosphatase control intersects with tumor suppressor networks. These findings suggest that targeting the negative regulation of 5-phosphatases could modulate oncogenic signaling.
Metabolic disease and insulin resistance
SKIP is a PIP3 5-phosphatase that regulates insulin signaling and GLUT4 exocytosis in skeletal muscle. Negative regulation of SKIP activity would be predicted to enhance insulin sensitivity by preserving PIP3, whereas excessive SKIP activity could contribute to insulin resistance. This makes GO:2001145 relevant to type 2 diabetes research.
Viral pathogenesis and immune evasion
HTLV-1 Tax down-regulates phosphatidylinositol 3,4,5-trisphosphate inositol phosphatases via NF-kappaB, linking negative regulation of 5-phosphatase activity to viral oncogenesis and immune evasion. By suppressing these enzymes, the virus sustains PIP3 signaling that supports T-cell proliferation and transformation.
Immune regulation and inflammation
SHIP1 and SHIP2 are key 5-phosphatases in immune cells, and their negative regulation influences cytokine responses and cell-mediated immunity. MicroRNAs such as miR-155 can influence cell-mediated immunity in vivo, providing a potential layer of indirect control over immune signaling pathways that include 5-phosphatases.
From negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of SHIP2 alter PIP3 levels and AKT activation? | SHIP2 knockout cell line |
| Does a specific phosphorylation site on SKIP control GLUT4 exocytosis? | SKIP point-mutation knock-in |
| Can a disease-associated SHIP2 variant change insulin sensitivity? | SHIP2 point-mutation knock-in |
| Where does SKIP localize during insulin stimulation? | Tagged knock-in of SKIP with fluorescent tag |
| Does overexpression of a 5-phosphatase mimic negative regulation loss? | Overexpression of SHIP2 or SKIP |
| Which genes are required for Tax-mediated repression of 5-phosphatases? | CRISPR knockout library screening in Tax-expressing cells |
How to Study the negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Lipidomics (LC-MS) | PIP3 and PI(3,4)P2 abundance | Assessing 5-phosphatase activity changes |
| Phospho-proteomics | AKT, MAPK, PTEN phosphorylation | Mapping downstream signaling |
| Live-cell imaging with PH-domain probes | PIP3 localization and dynamics | Visualizing GRP1 recruitment |
| GLUT4 translocation assay | Insulin-stimulated glucose transporter exocytosis | SKIP functional studies |
| RNA-seq | Transcriptional changes after perturbation | Identifying 5-phosphatase-regulated genes |
| CRISPR knockout screening | Gene requirements for a phenotype | Discovering negative regulators of 5-phosphatases |
| Western blot | Protein expression and phosphorylation | Validating SHIP2/SKIP loss or inhibition |
| qPCR | mRNA levels of 5-phosphatase genes | Measuring transcriptional repression by Tax |
Lipidomics and PIP3 measurement
Quantifying PIP3 and PI(3,4)P2 levels is essential to assess the functional impact of negative regulation of 5-phosphatase activity. Mass spectrometry-based lipidomics or radiolabeled lipid assays can measure these phosphoinositides in cells with CRISPR-engineered 5-phosphatase mutations.
Phospho-proteomics and signaling readouts
Phospho-proteomics can map changes in AKT, MAPK, and PTEN phosphorylation following perturbation of 5-phosphatase regulation. These readouts link GO:2001145 to downstream kinase networks and help identify compensatory feedback.
Imaging of PIP3 effectors and GLUT4 trafficking
Live-cell imaging of PIP3-binding pleckstrin homology domain probes, such as GRP1, can visualize PIP3 dynamics at the plasma membrane. In muscle cells, GLUT4 translocation assays directly report on SKIP-regulated insulin responses.
Transcriptomics and CRISPR screening
RNA-seq after CRISPR knockout of candidate regulators can reveal transcriptional programs controlled by 5-phosphatase activity. Pooled CRISPR library screening enables unbiased discovery of genes that negatively regulate 5-phosphatase expression or function.
How CRISPR Can Be Used to Study GO:2001145 negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity
Knockout
CRISPR knockout of INPPL1 (SHIP2), INPP5K (SKIP), or INPP5D (SHIP1) eliminates 5-phosphatase activity, effectively removing the target of negative regulation and allowing researchers to measure PIP3 accumulation and downstream AKT activation. Knockout models are foundational for testing whether a candidate regulator acts through this GO term.
Point Mutation
Point-mutation knock-in can ablate catalytic activity or specific regulatory phosphorylation sites in 5-phosphatases without altering protein abundance. Such models are critical to distinguish catalytic versus scaffolding functions of SHIP2 and SKIP in insulin signaling and cancer.
Knock-in
Tagged knock-in of endogenous 5-phosphatase genes with fluorescent or affinity tags enables real-time localization and interactome studies under physiological expression levels. This approach helps define where and when negative regulation occurs within the cell.
Overexpression
Overexpression of wild-type or mutant 5-phosphatases can mimic or reverse negative regulation, providing gain-of-function evidence for the role of PIP3 dephosphorylation in signaling. Overexpression models are useful for rescue experiments after knockout.
How EDITGENE Supports negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity Research
Researchers studying negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity-related genes often need to determine whether a candidate gene is causally involved in PIP3 regulation or simply correlated with signaling changes. EDITGENE provides the CRISPR tools and bioinformatics support to move from hypothesis to validated mechanism.
Contact EDITGENE today to design your custom CRISPR model for negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity research.
Frequently Asked Questions About negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity
What is GO:2001145?
GO:2001145 is a Gene Ontology biological process term for any process that stops, prevents, or reduces the frequency, rate, or extent of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity.
What does negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity mean?
It means the cell is reducing the ability of 5-phosphatase enzymes to remove the 5-phosphate from PIP3, thereby preserving PIP3 signaling.
What genes are involved in negative regulation of phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity?
Key genes include INPP5D (SHIP1), INPPL1 (SHIP2), INPP5K (SKIP), PTEN, PIK3CA, AKT1, and NFKB1, among others.
Which enzymes are targeted by GO:2001145?
The term targets phosphatidylinositol-3,4,5-trisphosphate 5-phosphatases such as SHIP1, SHIP2, and SKIP.
How is 5-phosphatase activity negatively regulated?
It can be negatively regulated by transcriptional repression, post-translational inhibition, competition with PI3K effectors, and feedback crosstalk with PTEN.
Why is PIP3 important in this process?
PIP3 is a lipid second messenger that activates AKT and drives glucose uptake and cell survival; 5-phosphatases remove it, so their negative regulation sustains PIP3 signals.
What diseases are linked to 5-phosphatase regulation?
Cancer, insulin resistance, immune dysregulation, and HTLV-1-associated pathogenesis have been linked to altered 5-phosphatase regulation.
How can CRISPR help study GO:2001145?
CRISPR knockout, point mutation, knock-in, and overexpression models allow causal testing of 5-phosphatase regulators and their effect on PIP3 signaling.
What is the role of SKIP in insulin signaling?
SKIP is a PIP3 5-phosphatase that regulates insulin signaling and GLUT4 exocytosis in skeletal muscle, making it a key node for metabolic studies.
Does SHIP2 inhibition affect cancer signaling?
Yes, SHIP2 inhibition alters redox-induced PI3K/AKT and MAP kinase pathways via PTEN over-activation in cervical cancer cells.
Conclusion
GO:2001145 provides a precise ontology framework for studying how cells suppress phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity to maintain PIP3 signaling. The interplay between SHIP1, SHIP2, SKIP, PTEN, and upstream growth factor pathways places this term at the center of metabolic, immune, and oncogenic signaling. CRISPR-based knockout, point-mutation, knock-in, and overexpression models, combined with lipidomics and phospho-proteomics, offer robust tools to dissect the mechanisms and disease relevance of this regulatory process. EDITGENE supports these efforts with custom cell model generation and bioinformatics services tailored to PI3K/AKT research.
References
- 1. Li H et al.. 2015. Phosphatidylinositol (3,4) bisphosphate-specific phosphatases and effector proteins: A distinct branch of PI3K signaling.. Cell Signal 27(9):1789-98 PMID: 26022180
- 2. Ijuin T et al.. 2012. Regulation of insulin signaling and glucose transporter 4 (GLUT4) exocytosis by phosphatidylinositol 3,4,5-trisphosphate (PIP3) phosphatase, skeletal muscle, and kidney enriched inositol polyphosphate phosphatase (SKIP).. J Biol Chem 287(10):6991-9 PMID: 22247557
- 3. Shirani K et al.. 2021. miR-155 influences cell-mediated immunity in Balb/c mice treated with aflatoxin M(1).. Drug Chem Toxicol 44(1):39-46 PMID: 30739504
- 4. Fukuda RI et al.. 2009. Human T-cell leukemia virus type I tax down-regulates the expression of phosphatidylinositol 3,4,5-trisphosphate inositol phosphatases via the NF-kappaB pathway.. J Biol Chem 284(5):2680-2689 PMID: 19047050
- 5. Azzi A. 2020. SHIP2 inhibition alters redox-induced PI3K/AKT and MAP kinase pathways via PTEN over-activation in cervical cancer cells.. FEBS Open Bio 10(10):2191-2205 PMID: 32881386
- 6. Venkateswarlu K et al.. 1998. Nerve growth factor- and epidermal growth factor-stimulated translocation of the ADP-ribosylation factor-exchange factor GRP1 to the plasma membrane of PC12 cells requires activation of phosphatidylinositol 3-kinase and the GRP1 pleckstrin homology domain.. Biochem J 335 ( Pt 1)(Pt 1):139-46 PMID: 9742223
