GO:0052629 phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0052629 describes the enzymatic removal of the 3-phosphate from phosphatidylinositol-3,5-bisphosphate (PI(3,5)P2) to generate phosphatidylinositol-5-phosphate (PI5P) and inorganic phosphate.
• This activity is a molecular_function carried out by myotubularin-related (MTMR) phosphatases, including MTMR3, MTMR4, MTMR14 (also known as hJUMPY), and the pseudophosphatase MTMR13 [4,5,7].
• PI(3,5)P2 turnover is central to lysosomal and endosomal membrane homeostasis, autophagy, and nutrient sensing [1,2,3].
• Dysregulation of PI(3,5)P2 3-phosphatase activity is linked to inflammatory bowel disease, COPD, and neurodevelopmental disorders [1,3,6].
• Assays for this activity typically use radiolabeled or fluorescent PI(3,5)P2 substrates and thin-layer chromatography or malachite green detection.
• CRISPR knockout, point-mutation, and knock-in models of MTMR genes enable causal dissection of PI(3,5)P2 signaling in disease [6,7].
Description
Phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity (GO:0052629) is a molecular_function that catalyzes the hydrolysis of phosphatidylinositol-3,5-bisphosphate (PI(3,5)P2) to phosphatidylinositol-5-phosphate (PI5P) and phosphate. This reaction is a key node in phosphoinositide signaling, controlling the abundance of two distinct lipid messengers that regulate endosomal and lysosomal dynamics. The activity is attributed to members of the myotubularin-related (MTMR) family of phosphatases, which share a conserved catalytic motif but differ in substrate specificity and subcellular localization [4,5]. Researchers study GO:0052629 because PI(3,5)P2 and PI5P are low-abundance but potent regulators of membrane trafficking, autophagy, and ion homeostasis [1,3,7]. Perturbations in this activity have been implicated in inflammatory diseases such as COPD and IBD, as well as in neurodevelopmental and neurodegenerative conditions [1,3,6]. Understanding the enzymatic mechanism, regulation, and disease relevance of this activity requires robust biochemical assays and genetically defined cell models. This article integrates the QuickGO definition with verified literature to provide a research-grade overview of GO:0052629, including its catalytic mechanism, key genes, disease associations, and experimental strategies for functional studies.
phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity At A Glance
| GO ID | GO:0052629 |
|---|---|
| GO term | phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity |
| Ontology | molecular_function |
| Synonym | none |
| Major function | Catalyzes the dephosphorylation of PI(3,5)P2 at the 3-position to produce PI5P and phosphate |
| Substrate | 1-phosphatidyl-1D-myo-inositol 3,5-bisphosphate (PI(3,5)P2) |
| Products | 1-phosphatidyl-1D-myo-inositol 5-phosphate (PI5P), phosphate, and 2 H+ |
| Representative enzymes | MTMR3, MTMR4, MTMR14, and pseudophosphatase MTMR13 [4,5,7] |
| Cellular context | Endosomal and lysosomal membranes; autophagy and nutrient sensing [1,2,3] |
| Disease links | Inflammatory bowel disease, COPD, neurodevelopmental disorders [1,3,6] |
What Is GO:0052629?
GO:0052629 phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity is defined as the catalysis of the reaction: 1-phosphatidyl-1D-myo-inositol 3,5-bisphosphate + H2O = 1-phosphatidyl-1D-myo-inositol 5-phosphate + phosphate + 2 H+. In simpler terms, it is the enzyme activity that removes the phosphate group at the 3-position of the inositol ring from PI(3,5)P2, yielding PI5P and free phosphate. This activity belongs to the molecular_function ontology and is distinct from other phosphoinositide phosphatases that act on different positions or substrates [4,5].
Why Is phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity Important in Cell Biology?
GO:0052629 is important because it controls the balance between PI(3,5)P2 and PI5P, two signaling lipids that govern endolysosomal function, autophagy, and cellular responses to nutrients. Dysregulation of this activity has been linked to chronic inflammatory diseases such as COPD and IBD, as well as to neurodevelopmental and neurodegenerative disorders [1,3,6]. Thus, understanding this enzymatic activity provides mechanistic insight into disease pathogenesis and identifies potential therapeutic targets.
• Regulates endosomal and lysosomal membrane homeostasis through PI(3,5)P2 turnover.
• Controls autophagy and nutrient sensing pathways relevant to inflammatory bowel disease.
• Modulates macrophage polarization and intrapulmonary inflammation in COPD models.
• Impacts calcium homeostasis via myotubularin-related proteins.
• Associated with neurodevelopmental, neuromuscular, and neurodegenerative disorders.
• Provides a biochemical target for assays of phosphoinositide phosphatase activity.
• Involves pseudophosphatases that can modulate signaling without catalytic activity [4,5].
• Enables CRISPR-based dissection of gene function in disease models [6,7].
Molecular Mechanism of phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity
Substrate recognition and binding
In simple terms: The enzyme grabs PI(3,5)P2 and positions it for phosphate removal.
The enzyme binds phosphatidylinositol-3,5-bisphosphate (PI(3,5)P2) at the membrane interface, recognizing the inositol headgroup and the two phosphate groups at positions 3 and 5. This binding is mediated by conserved residues in the catalytic domain of myotubularin-related phosphatases [4,5].
Catalytic dephosphorylation at the 3-position
In simple terms: The enzyme cuts off the phosphate at the 3-position of the lipid.
The catalytic cysteine in the CX5R motif performs a nucleophilic attack on the 3-phosphate of PI(3,5)P2, forming a covalent enzyme-substrate intermediate that is subsequently hydrolyzed to release PI5P and phosphate [2,4]. This reaction requires water and produces two protons.
Product release and membrane dynamics
In simple terms: The products are released and the lipid composition of the membrane changes.
After catalysis, PI5P and phosphate are released, altering the local phosphoinositide composition of endosomal and lysosomal membranes. This conversion is critical for recruiting effector proteins that regulate membrane trafficking and autophagy [1,3].
Regulation by pseudophosphatases and protein partners
In simple terms: Other proteins can turn the enzyme on or off.
Pseudophosphatases such as MTMR13 lack catalytic activity but can bind to active phosphatases and modulate their function or localization [4,5]. Additionally, myotubularin-related proteins interact with calcium signaling machinery, linking this activity to Ca2+ homeostasis.
Key Genes Involved in GO:0052629 phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity
The following genes encode proteins that carry out or regulate phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity (GO:0052629) or are closely associated with its biological functions.
| Gene | Major Role | Research Relevance |
|---|---|---|
| MTMR3 | Phosphatidylinositol-3,5-bisphosphate 3-phosphatase; regulates autophagy and endosomal trafficking | Implicated in inflammatory bowel disease and autophagy studies [1,2] |
| MTMR4 | Phosphatidylinositol-3,5-bisphosphate 3-phosphatase; controls endosomal dynamics | Linked to nutrient sensing and lysosome function |
| MTMR14 | Phosphatidylinositol-3,5-bisphosphate 3-phosphatase; also known as hJUMPY | Depletion aggravates COPD-like inflammation in models |
| MTMR13 | Pseudophosphatase; modulates active myotubularins | Studied for roles in disease and pseudophosphatase biology [4,5] |
| MTMR2 | Myotubularin-related phosphatase; lipid signaling | Associated with neurodevelopmental disorders |
| MTM1 | Myotubularin; phosphoinositide phosphatase | Linked to neuromuscular disorders |
| MTMR1 | Myotubularin-related phosphatase | Potential regulator of phosphoinositide pools |
| MTMR6 | Myotubularin-related phosphatase | Involved in calcium homeostasis |
| MTMR7 | Myotubularin-related phosphatase | Studied in pseudophosphatase contexts |
| MTMR8 | Myotubularin-related phosphatase | Associated with autophagy and membrane trafficking |
| MTMR9 | Pseudophosphatase; interacts with active MTMRs | Modulates phosphatase activity |
| MTMR10 | Myotubularin-related protein | Potential role in lipid signaling |
| MTMR11 | Myotubularin-related protein | Less characterized; may affect phosphoinositide metabolism |
| MTMR12 | Pseudophosphatase; binds MTM1 | Studied for pseudophosphatase function |
| MTMR15 | Myotubularin-related protein | Potential involvement in disease |
| VAC14 | Regulates PI(3,5)P2 synthesis | Component of the PIKfyve complex affecting substrate availability |
| PIKfyve | Synthesizes PI(3,5)P2 | Provides substrate for GO:0052629 |
| FIG4 | Phosphatase that regulates PI(3,5)P2 levels | Mutated in neurodevelopmental disorders |
How Is phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity Regulated?
The activity of phosphatidylinositol-3,5-bisphosphate 3-phosphatase is regulated by nutrient availability and signaling lipid conversion, as shown by Ebner et al. (2023), who demonstrated that lysosomal function is controlled by dynamic changes in phosphoinositide species. Pseudophosphatases such as MTMR13 can modulate the activity or localization of active phosphatases, providing an additional layer of regulation [4,5]. Furthermore, myotubularin-related proteins are linked to calcium homeostasis, suggesting that Ca2+ signals may influence their function.
phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| MTMR3 | Inflammatory bowel disease; autophagy dysregulation | Knockout intestinal epithelial cells or organoids |
| MTMR14 | COPD; macrophage M1 polarization | Knockout mouse model of emphysema |
| MTMR2 | Neurodevelopmental disorders | Knockout neuronal cells |
| MTM1 | Neuromuscular disorders | Knock-in mouse models |
| MTMR13 | Pseudophosphatase-related disease | Point-mutation knock-in cells [4,5] |
Inflammatory bowel disease and autophagy
Alterations in autophagy and gut microbiota contribute to inflammatory bowel disease (IBD), and phosphoinositide signaling is critical for autophagosome formation and maturation. MTMR3, which possesses phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity, regulates autophagy and may influence IBD pathogenesis [1,2].
Chronic obstructive pulmonary disease (COPD)
MTMR14 depletion aggravates intrapulmonary inflammation and emphysema in experimental COPD by activating macrophage M1 polarization. This links GO:0052629 activity to inflammatory lung disease and macrophage function.
Neurodevelopmental and neurodegenerative disorders
Defective autophagy and phosphoinositide metabolism are associated with a spectrum of neurodevelopmental, neuromuscular, and neurodegenerative disorders. Myotubularin-related proteins, including those with 3-phosphatase activity, are implicated in these conditions [3,7].
Pseudophosphatase-related pathologies
Pseudophosphatases such as MTMR13 can modulate signaling pathways and are implicated in disease, highlighting the importance of non-catalytic regulation of GO:0052629 [4,5].
From phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of MTMR14 alter PI(3,5)P2 levels? | MTMR14 knockout cell line |
| Does a catalytic-dead mutation affect autophagy? | Point-mutation knock-in of MTMR3 |
| Can wild-type MTMR3 rescue lipid defects? | Overexpression of tagged MTMR3 |
| How does MTMR13 modulate active phosphatases? | Knock-in of tagged MTMR13 |
| What is the role of MTMR14 in macrophage polarization? | Conditional knockout in macrophages |
| Does PI(3,5)P2 3-phosphatase activity affect calcium signaling? | Knockout of MTMR6 in cell lines |
How to Study the phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Malachite green assay | Release of free phosphate from PI(3,5)P2 | In vitro phosphatase activity |
| Thin-layer chromatography | Conversion of PI(3,5)P2 to PI5P | Biochemical characterization |
| Mass spectrometry lipidomics | Levels of PI(3,5)P2 and PI5P | Cellular lipid profiling |
| CRISPR knockout screening | Gene requirements for autophagy | Functional genomics |
| Immunofluorescence | Endosomal/lysosomal marker distribution | Membrane trafficking studies |
| Western blot | Autophagy markers (LC3, p62) | Autophagy flux analysis |
| qRT-PCR | Expression of MTMR genes | Transcriptional regulation |
| Calcium imaging | Intracellular Ca2+ dynamics | Link to myotubularin function |
Biochemical phosphatase assays
Phosphoinositide phosphatase activity can be measured using radiolabeled or fluorescent PI(3,5)P2 substrates followed by thin-layer chromatography or malachite green detection of released phosphate. These assays provide direct evidence of GO:0052629 activity in vitro.
Lipidomics and mass spectrometry
Mass spectrometry-based lipidomics enables quantification of PI(3,5)P2 and PI5P levels in cells and tissues, revealing changes in substrate and product pools upon genetic manipulation.
CRISPR-based genetic screens
CRISPR knockout screens can identify genes that regulate PI(3,5)P2 homeostasis and autophagy, linking candidate genes to GO:0052629-related phenotypes [1,3].
Imaging of endolysosomal dynamics
Fluorescence microscopy of endosomal and lysosomal markers in cells with altered phosphatase activity reveals defects in membrane trafficking and autophagy [2,6].
How CRISPR Can Be Used to Study GO:0052629 phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity
Knockout
CRISPR knockout of MTMR genes such as MTMR14 or MTMR3 eliminates phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity, enabling studies of lipid accumulation and downstream phenotypes like autophagy blockade or inflammation [6,1].
Point Mutation
Introducing catalytic-dead point mutations (e.g., in the CX5R motif) of MTMR genes via CRISPR allows separation of enzymatic activity from scaffolding functions, clarifying the specific contribution of GO:0052629 to cellular processes [4,5].
Knock-in
Knock-in of epitope tags or fluorescent reporters at endogenous MTMR loci enables real-time tracking of protein localization and interaction with PI(3,5)P2-rich membranes [2,7].
Overexpression
CRISPR-mediated overexpression or cDNA delivery of wild-type or mutant MTMR genes can rescue or exacerbate phenotypes, providing gain-of-function evidence for the role of GO:0052629 in disease models [2,6].
How EDITGENE Supports phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity Research
Researchers studying phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity-related genes often need to determine whether a candidate gene is causally involved in lipid signaling, autophagy, or disease phenotypes. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity research.
Frequently Asked Questions About phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity
What is phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity?
It is the enzyme activity (GO:0052629) that removes the 3-phosphate from PI(3,5)P2 to produce PI5P and phosphate.
What genes are involved in phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity?
Genes include MTMR3, MTMR4, MTMR14, and the pseudophosphatase MTMR13, among other myotubularin-related genes [4,5,7].
Which diseases are linked to GO:0052629?
Inflammatory bowel disease, COPD, and neurodevelopmental disorders have been associated with dysregulated PI(3,5)P2 signaling [1,3,6].
How is phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity measured?
It is measured using biochemical assays with radiolabeled or fluorescent PI(3,5)P2 and detection of released phosphate.
What is the role of MTMR14 in COPD?
MTMR14 depletion aggravates intrapulmonary inflammation and emphysema in experimental COPD by activating macrophage M1 polarization.
How does PI(3,5)P2 3-phosphatase affect autophagy?
By converting PI(3,5)P2 to PI5P, it regulates endosomal and lysosomal membrane dynamics essential for autophagosome maturation [1,2].
What are pseudophosphatases in this context?
Pseudophosphatases such as MTMR13 lack catalytic activity but can modulate active phosphatases and signaling [4,5].
Can CRISPR be used to study GO:0052629?
Yes, CRISPR knockout, point mutation, and knock-in models enable precise dissection of gene function in lipid signaling [6,7].
What is the substrate of phosphatidylinositol-3,5-bisphosphate 3-phosphatase?
The substrate is 1-phosphatidyl-1D-myo-inositol 3,5-bisphosphate (PI(3,5)P2).
Where in the cell does this activity occur?
It occurs primarily on endosomal and lysosomal membranes [2,3].
Conclusion
GO:0052629 phosphatidylinositol-3,5-bisphosphate 3-phosphatase activity is a critical enzymatic function that controls the balance of PI(3,5)P2 and PI5P, influencing endolysosomal trafficking, autophagy, and cellular responses to nutrients. Its dysregulation is linked to inflammatory diseases such as COPD and IBD, as well as neurodevelopmental disorders [1,3,6]. Continued research using biochemical assays and CRISPR-engineered models will further elucidate its mechanistic roles and therapeutic potential [8,7].
References
- 1. Larabi A et al.. 2020. New insights into the interplay between autophagy, gut microbiota and inflammatory responses in IBD.. Autophagy 16(1):38-51 PMID: 31286804
- 2. Ebner M et al.. 2023. Nutrient-regulated control of lysosome function by signaling lipid conversion.. Cell 186(24):5328-5346.e26 PMID: 37883971
- 3. Deneubourg C et al.. 2022. The spectrum of neurodevelopmental, neuromuscular and neurodegenerative disorders due to defective autophagy.. Autophagy 18(3):496-517 PMID: 34130600
- 4. Mattei AM et al.. 2021. The Roles of Pseudophosphatases in Disease.. Int J Mol Sci 22(13) PMID: 34203203
- 5. Liu D et al.. 2022. The progress of research into pseudophosphatases.. Front Public Health 10:965631 PMID: 36106167
- 6. Zhang J et al.. 2025. MTMR14 depletion aggravates intrapulmonary inflammation and emphysema in experimental COPD through activating macrophage M1 polarization.. Respir Res 26(1):238 PMID: 40640787
- 7. Dai N et al.. 2024. Interplay between myotubularins and Ca(2+) homeostasis.. Biochim Biophys Acta Mol Cell Res 1871(5):119739 PMID: 38710289
- 8. Taylor GS et al.. 2004. Assaying phosphoinositide phosphatases.. Methods Mol Biol 284:217-27 PMID: 15173619
