GO:0141013 purine nucleotide import into lysosome: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0141013 describes the directed import of purine nucleotides from the cytosol across the lysosomal membrane into the lysosome.
• This process is distinct from general lysosomal degradation and is mediated by specific transport machinery that remains incompletely characterized.
• VNUT (SLC17A9) is a well-studied lysosomal nucleotide transporter that mediates ATP uptake and release, and its function is linked to immune cell differentiation.
• Lysosomal purine nucleotide import influences signaling pathways, including P2X7R-JNK-FOXO3a-Eomes in T helper 1 cells.
• Defects in lysosomal transport are associated with lysosomal storage disorders and altered drug susceptibility, as shown for Niemann-Pick C1 and pfmdr1 [4,8].
• CRISPR-based models (knockout, knock-in, overexpression) enable causal dissection of genes involved in lysosomal purine nucleotide import [1,4].
Description
Purine nucleotide import into lysosome (GO:0141013) is a biological process defined as the directed movement of purine nucleotides from the cytosol across the lysosomal membrane into the lysosomal lumen. This process is essential for maintaining lysosomal nucleotide pools, which participate in signaling, energy homeostasis, and substrate degradation. Unlike bulk lysosomal degradation, this import is a selective, membrane-transport-dependent event that requires specific transporter proteins. Researchers study GO:0141013 to understand how lysosomes regulate nucleotide-dependent signaling and how defects in this process contribute to disease [1,4]. The vesicular nucleotide transporter VNUT (SLC17A9) is a key mediator of ATP uptake into lysosomes and subsequent release, linking lysosomal purine nucleotide import to T cell differentiation and immune regulation. Additionally, lysosomal transport pathways are implicated in lipid metabolism and drug response, as exemplified by Niemann-Pick C1 and plasmodial pfmdr1 expression in mammalian cells [4,8]. Thus, GO:0141013 represents a convergence point for lysosomal biology, nucleotide signaling, and therapeutic targeting [1,4,8].
purine nucleotide import into lysosome At A Glance
| GO ID | GO:0141013 |
|---|---|
| GO term | purine nucleotide import into lysosome |
| Ontology | biological_process |
| Synonym | none |
| Major function | Transport of purine nucleotides from cytosol into lysosome |
| Cellular location | Lysosomal membrane |
| Key transporter | VNUT (SLC17A9) |
| Associated processes | Nucleotide signaling, lysosomal degradation, immune cell differentiation |
| Disease relevance | Lysosomal storage disorders, cancer, drug susceptibility [4,8] |
What Is GO:0141013?
GO:0141013, purine nucleotide import into lysosome, is the directed import of purine nucleotide from the cytosol, across the lysosomal membrane, into the lysosome. This process requires energy and specific transport proteins to move nucleotides against or along their concentration gradient into the lysosomal lumen.
Why Is purine nucleotide import into lysosome Important in Cell Biology?
Understanding purine nucleotide import into lysosome is critical because lysosomal nucleotide pools regulate diverse cellular processes, including autophagy, immune signaling, and drug responses [1,4,8]. Dysregulation of this transport can alter T cell differentiation and contribute to inflammatory diseases. Moreover, lysosomal transport proteins influence the efficacy of chemotherapeutic agents, as shown by pfmdr1-mediated chloroquine susceptibility. Therefore, GO:0141013 is a promising target for therapeutic intervention and a key area for basic and translational research [1,4,8].
• Regulates lysosomal ATP levels and purinergic signaling.
• Modulates T helper 1 cell differentiation via P2X7R-JNK-FOXO3a-Eomes cascade.
• Influences lysosomal degradation and autophagy.
• Affects drug susceptibility, including chloroquine response.
• Implicated in lysosomal storage disorders such as Niemann-Pick disease.
• Potential target for cancer therapy under hypoxia.
• Required for normal lysosomal function and cellular homeostasis.
• Provides a mechanism for nucleotide exchange between cytosol and lysosome.
• Can be studied using CRISPR knockout and overexpression models [1,4].
• Links metabolism to immune regulation.
What Happens During purine nucleotide import into lysosome?
Recognition and Binding of Purine Nucleotides
In simple terms: The transporter on the lysosome surface grabs purine nucleotides from the cytosol.
The first step involves specific binding of purine nucleotides, such as ATP, to a transporter protein on the cytosolic side of the lysosomal membrane. VNUT (SLC17A9) has been shown to mediate ATP uptake into lysosomes, and its function is critical for subsequent release. This binding is likely selective for purine nucleotides over pyrimidines, although the exact structural determinants remain to be fully elucidated.
Translocation Across the Lysosomal Membrane
In simple terms: The nucleotide is moved through the membrane into the lysosome.
Following binding, the transporter undergoes conformational changes to translocate the nucleotide across the lipid bilayer into the lysosomal lumen. This process may be driven by proton gradients or ATP hydrolysis, similar to other lysosomal transporters. The imported nucleotides can then participate in lysosomal signaling or be released into the cytosol via vesicular exocytosis.
Regulation by Cellular Signals
In simple terms: Cellular signals can turn this import process up or down.
The import of purine nucleotides into lysosomes is regulated by cellular metabolic status and signaling pathways. For instance, VNUT-mediated ATP release suppresses T helper 1 differentiation via the P2X7R-JNK-FOXO3a-Eomes cascade, indicating that the import process is coupled to immune signaling. Additionally, coenzyme-depleting nanocarriers can enhance redox cancer therapy under hypoxia, suggesting that lysosomal nucleotide transport may be modulated by redox status.
Downstream Effects on Lysosomal Function
In simple terms: Once inside, the nucleotides affect how the lysosome works.
Imported purine nucleotides contribute to lysosomal functions such as acidification, enzyme activity, and membrane stability. They can also serve as substrates for further degradation or as signaling molecules that influence gene expression. Disruption of this import can lead to lysosomal dysfunction and disease, as seen in Niemann-Pick C1 deficiency.
Key Genes Involved in GO:0141013 purine nucleotide import into lysosome
The following genes and proteins are experimentally linked to purine nucleotide import into lysosome or related lysosomal transport processes.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SLC17A9 (VNUT) | Vesicular nucleotide transporter mediating ATP uptake into lysosomes | Key mediator of lysosomal purine nucleotide import; linked to T cell differentiation |
| P2RX7 (P2X7R) | ATP-gated ion channel involved in signaling downstream of VNUT | Mediates P2X7R-JNK-FOXO3a-Eomes cascade in T cells |
| JNK | Stress-activated protein kinase | Part of signaling cascade downstream of VNUT-mediated ATP release |
| FOXO3A | Transcription factor | Regulates Eomes expression in T helper 1 differentiation |
| EOMES | Transcription factor | Controls T helper 1 cell differentiation |
| NPC1 | Lysosomal cholesterol transporter | Mutations cause Niemann-Pick disease; role in adrenal steroidogenesis |
| PFMDR1 | Plasmodial multidrug resistance transporter | Expression in mammalian cells increases chloroquine susceptibility |
| NSF | AAA+ ATPase involved in membrane fusion | Required for transport from early to late endosomes |
| aFGF | Acidic fibroblast growth factor | Nuclear translocation studied as model for transport |
| mAspAT | Mitochondrial aspartate aminotransferase precursor | Degradation studied in lysosomes |
| N-acetylchitooligosaccharide transporters | Lysosomal import of oligosaccharides | Model for lysosomal transport mechanisms |
| Coenzyme-depleting nanocarriers | Redox cancer therapy | Modulate lysosomal function under hypoxia |
| LAMP1 | Lysosomal membrane protein | Marker for lysosomal localization |
| LAMP2 | Lysosomal membrane protein | Marker for lysosomal localization |
| Rab7 | Late endosomal GTPase | Regulates lysosomal transport |
| V-ATPase | Proton pump | Provides driving force for lysosomal transport |
| Clathrin | Vesicle coat protein | Involved in endosomal transport |
| Dynamin | GTPase | Mediates vesicle scission |
How Is purine nucleotide import into lysosome Regulated?
The import of purine nucleotides into lysosomes is regulated at multiple levels. Transcriptional regulation of SLC17A9 (VNUT) controls the capacity for ATP uptake, and its expression is modulated during T cell activation. Post-translational modifications, such as phosphorylation by JNK, may regulate transporter activity or trafficking. Additionally, the proton gradient maintained by V-ATPase provides the energy for transport, and changes in lysosomal pH can affect import efficiency. Redox status also influences lysosomal function, as coenzyme-depleting nanocarriers enhance redox cancer therapy under hypoxia, potentially by altering nucleotide transport. Furthermore, the expression of pfmdr1 in mammalian cells increases susceptibility to chloroquine, suggesting that drug transporters can modulate lysosomal nucleotide import.
purine nucleotide import into lysosome and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC17A9 (VNUT) | T cell differentiation, immune regulation | Knockout mice or T cell lines |
| NPC1 | Niemann-Pick disease type C | Patient fibroblasts or NPC1 KO cells |
| PFMDR1 | Chloroquine susceptibility | Transfected mammalian cells |
| P2RX7 | Inflammatory signaling | P2X7R KO macrophages |
| FOXO3A | T cell differentiation | FOXO3A KO T cells |
Lysosomal Storage Disorders
Defects in lysosomal transport proteins can lead to lysosomal storage disorders. For example, mutations in NPC1 cause Niemann-Pick type C disease, characterized by impaired cholesterol transport and adrenal steroidogenesis. Although direct links between purine nucleotide import and these disorders are still emerging, the shared lysosomal membrane environment suggests that altered nucleotide transport could contribute to disease pathology.
Cancer and Drug Resistance
Lysosomal purine nucleotide import may influence cancer cell survival under stress. Coenzyme-depleting nanocarriers enhance redox cancer therapy under hypoxia, indicating that lysosomal nucleotide pools are important for redox homeostasis. Additionally, expression of the plasmodial pfmdr1 gene in mammalian cells increases susceptibility to chloroquine, highlighting how lysosomal transport can modulate drug responses.
Immune Regulation and Inflammation
VNUT-mediated ATP release from lysosomes suppresses T helper 1 differentiation via the P2X7R-JNK-FOXO3a-Eomes signaling cascade. This suggests that dysregulated purine nucleotide import into lysosomes could contribute to autoimmune or inflammatory diseases by altering T cell responses.
From purine nucleotide import into lysosome-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does SLC17A9 mediate lysosomal ATP import? | SLC17A9 knockout cell line |
| What is the role of VNUT in T cell differentiation? | VNUT knockout mice |
| How does NPC1 affect lysosomal transport? | NPC1 mutant fibroblasts |
| Does pfmdr1 expression alter drug susceptibility? | pfmdr1-transfected cells |
| Can redox status modulate lysosomal nucleotide import? | Coenzyme-depleting nanocarrier treatment |
| Is NSF required for lysosomal transport? | NSF mutant cell lines |
How to Study the purine nucleotide import into lysosome Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorescent nucleotide analogs | Lysosomal import rate | Transport assays in isolated lysosomes |
| CRISPR knockout | Gene function | SLC17A9 KO in T cells |
| Co-immunoprecipitation | Protein interactions | VNUT-JNK interaction |
| Live-cell imaging | Real-time transport | Lysosomal pH and nucleotide flux |
| RNA-seq | Gene expression changes | T cell differentiation |
| Proteomics | Lysosomal membrane composition | Identification of novel transporters |
| Chloroquine susceptibility assay | Drug response | pfmdr1-transfected cells |
| Redox stress assay | Hypoxia response | Coenzyme-depleting nanocarriers |
Fluorescent Nucleotide Analogs
Fluorescent N-acetylchitooligosaccharide analogs have been used to study lysosomal import in rat liver lysosomes, providing a model for tracking purine nucleotide uptake. Similar approaches with fluorescent ATP analogs can visualize real-time import into lysosomes.
Genetic Knockout and Knockdown
CRISPR-Cas9 knockout of candidate transporters such as SLC17A9 allows functional assessment of purine nucleotide import. Knockout of VNUT impairs ATP release and alters T cell differentiation, demonstrating the utility of this approach.
Proteomics and Interaction Studies
Proteomic analysis of lysosomal membranes can identify novel transporters and regulatory proteins. Co-immunoprecipitation of VNUT with signaling molecules like JNK can reveal interaction networks.
Live-Cell Imaging
Live-cell imaging with pH-sensitive or nucleotide-sensitive dyes can monitor lysosomal import in real time. This method has been applied to study lysosomal transport of various substrates.
How CRISPR Can Be Used to Study GO:0141013 purine nucleotide import into lysosome
Knockout
CRISPR knockout of SLC17A9 (VNUT) in T cells or other cell types can abolish lysosomal ATP import, leading to impaired P2X7R signaling and altered differentiation. Knockout of NPC1 can model Niemann-Pick disease and assess lysosomal transport defects.
Point Mutation
Introducing point mutations in SLC17A9 or NPC1 can mimic disease-associated variants and test their impact on transport activity. For example, mutations in NPC1 that cause Niemann-Pick disease can be recreated to study lysosomal dysfunction.
Knock-in
Knock-in of tagged SLC17A9 (e.g., GFP or HA) allows visualization and purification of the transporter for interaction studies. This approach can also be used to express disease-relevant mutants at endogenous levels.
Overexpression
Overexpression of SLC17A9 or pfmdr1 can enhance lysosomal nucleotide import and alter drug susceptibility, as shown for chloroquine in pfmdr1-transfected cells. Overexpression models are useful for gain-of-function studies [1,8].
How EDITGENE Supports purine nucleotide import into lysosome Research
Researchers studying purine nucleotide import into lysosome-related genes often need to determine whether a candidate gene is causally involved in transport, signaling, or disease. EDITGENE provides comprehensive CRISPR-based services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for purine nucleotide import into lysosome research.
Frequently Asked Questions About purine nucleotide import into lysosome
What is GO:0141013?
GO:0141013 is the biological process of purine nucleotide import into lysosome, defined as the directed import of purine nucleotides from the cytosol across the lysosomal membrane into the lysosome.
What genes are involved in purine nucleotide import into lysosome?
Key genes include SLC17A9 (VNUT), P2RX7, JNK, FOXO3A, EOMES, and NPC1, among others [1,4].
How does VNUT mediate lysosomal ATP import?
VNUT (SLC17A9) is a vesicular nucleotide transporter that mediates ATP uptake into lysosomes and subsequent release, influencing T cell differentiation.
What diseases are associated with lysosomal purine nucleotide transport?
Lysosomal storage disorders like Niemann-Pick disease, cancer, and immune dysregulation have been linked to lysosomal transport defects [1,3,4,8].
What methods are used to study purine nucleotide import into lysosome?
Fluorescent nucleotide analogs, CRISPR knockout, live-cell imaging, and proteomics are commonly used [1,2].
Can CRISPR be used to study GO:0141013?
Yes, CRISPR knockout, knock-in, and overexpression models are powerful tools to dissect gene function in lysosomal purine nucleotide import [1,4,8].
What is the role of P2X7R in lysosomal ATP signaling?
P2X7R is an ATP-gated ion channel that mediates downstream signaling from VNUT-mediated ATP release, affecting T helper 1 differentiation.
How does NPC1 relate to lysosomal transport?
NPC1 is a lysosomal cholesterol transporter; mutations cause Niemann-Pick disease and affect adrenal steroidogenesis, serving as a model for lysosomal transport studies.
Is pfmdr1 involved in lysosomal drug transport?
Expression of plasmodial pfmdr1 in mammalian cells increases susceptibility to chloroquine, indicating a role in lysosomal drug transport.
What are the research tools for lysosomal nucleotide import?
Tools include fluorescent analogs, CRISPR screens, and coenzyme-depleting nanocarriers for redox studies [2,3].
Conclusion
GO:0141013, purine nucleotide import into lysosome, is a fundamental biological process that regulates lysosomal nucleotide pools and downstream signaling. Key mediators such as VNUT (SLC17A9) and associated pathways like P2X7R-JNK-FOXO3a-Eomes have been experimentally linked to immune regulation and disease. Understanding this process offers insights into lysosomal storage disorders, cancer, and drug resistance [3,4,8]. CRISPR-based models and advanced imaging techniques are essential for further dissecting the molecular mechanisms and identifying therapeutic targets [1,2].
References
- 1. Wu B et al.. 2025. VNUT-mediated ATP release suppresses T helper 1 (T(H)1) cell differentiation via the P2X7R-JNK-FOXO3a-Eomes signaling cascade.. Sci Adv 11(51):eadz7600 PMID: 41417887
- 2. Bouzidi Y et al.. 2024. Transport of N-acetylchitooligosaccharides and fluorescent N-acetylchitooligosaccharide analogs into rat liver lysosomes.. Glycobiology 34(2) PMID: 38070184
- 3. Li Y et al.. 2023. Coenzyme-depleting nanocarriers for enhanced redox cancer therapy under hypoxia.. J Colloid Interface Sci 641:135-145 PMID: 36931212
- 4. Gévry NY et al.. 2002. The role and regulation of the Niemann-Pick C1 gene in adrenal steroidogenesis.. Endocr Res 28(4):403-12 PMID: 12530642
- 5. Cao Y et al.. 1993. Characterization of the nuclear translocation of acidic fibroblast growth factor.. J Cell Sci 104 ( Pt 1):77-87 PMID: 7680660
- 6. Robinson LJ et al.. 1997. NSF is required for transport from early to late endosomes.. J Cell Sci 110 ( Pt 17):2079-87 PMID: 9378758
- 7. Flückiger J et al.. 1988. Degradation of the precursor of mitochondrial aspartate aminotransferase in chicken embryo fibroblasts.. J Biol Chem 263(9):4131-8 PMID: 3346240
- 8. van Es HH et al.. 1994. Expression of the plasmodial pfmdr1 gene in mammalian cells is associated with increased susceptibility to chloroquine.. Mol Cell Biol 14(4):2419-28 PMID: 7511206
