GO:1990130 GATOR1 complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1990130 (GATOR1 complex) is a GTPase-activating protein (GAP) complex that regulates TORC1 signaling by interacting with the Rag GTPase.
• In humans, GATOR1 is composed of DEPDC5, NPRL2, and NPRL3; in S. cerevisiae, the orthologous SEACIT complex contains Iml1p, Npr2p, and Npr3p.
• GATOR1 functions as a negative regulator of mTORC1, acting on the Rag GTPases to inhibit TORC1 under nutrient-poor conditions.
• Germline variants in GATOR1 genes are major genetic causes of focal epilepsies, including familial focal epilepsy with variable foci (FFEVF) [3,4].
• GATOR1 also modulates sensitivity to chemotherapeutic agents such as cisplatin, linking it to cancer biology.
• Recent structural studies reveal that GATOR1 assembles into a lysosomal KICSTOR-GATOR1-SAMTOR supercomplex that integrates nutrient signals to control mTORC1.
Description
The GATOR1 complex (GO:1990130) is a conserved heterotrimeric GTPase-activating protein (GAP) complex that regulates TORC1 signaling by interacting with the Rag GTPase. It is defined in QuickGO as a cellular component that acts as a GAP for Rag GTPases, thereby inhibiting TORC1 under conditions of amino acid or nutrient limitation. In humans, GATOR1 consists of DEPDC5, NPRL2, and NPRL3, while in Saccharomyces cerevisiae the orthologous complex is called SEACIT and contains Iml1p, Npr2p, and Npr3p. Because mTORC1 is a central controller of cell growth, proliferation, and metabolism, GATOR1 is a critical node in nutrient-sensing pathways. Researchers study GATOR1 because its dysfunction is directly linked to human disease. Germline mutations in DEPDC5, NPRL2, and NPRL3 cause focal epilepsies, including familial focal epilepsy with variable foci (FFEVF) and other GATOR1-related epilepsies [3,4,5]. Beyond epilepsy, GATOR1 activity influences cancer cell responses to chemotherapy, as loss of GATOR1 components alters cisplatin sensitivity. Structural and biochemical work has revealed how GATOR1 engages the lysosomal nutrient-sensing machinery, including KICSTOR and SAMTOR, to control mTORC1. This article provides a research-grade overview of GO:1990130, covering its definition, composition, molecular mechanism, key genes, regulation, disease relevance, and experimental methods. All statements are based on published literature and the QuickGO definition, with inline citations to verified PubMed records.
GATOR1 complex At A Glance
| GO ID | GO:1990130 |
|---|---|
| GO term | GATOR1 complex |
| Ontology | cellular_component |
| Synonym | IML1 complex; SEACIT complex |
| Major function | GTPase-activating protein (GAP) complex that regulates TORC1 signaling by interacting with the Rag GTPase |
| Human subunits | DEPDC5, NPRL2, NPRL3 |
| S. cerevisiae subunits | Iml1p, Npr2p, Npr3p |
| Associated disease | Focal epilepsies, including familial focal epilepsy with variable foci (FFEVF) |
| Regulatory target | Rag GTPases and mTORC1/TORC1 signaling |
What Is GO:1990130?
GO:1990130 (GATOR1 complex) is a cellular component defined as a GTPase-activating protein (GAP) complex that regulates TORC1 signaling by interacting with the Rag GTPase. In human cells, the GATOR1 complex consists of DEPDC5, NPRL2, and NPRL3. In S. cerevisiae, this complex is referred to as SEACIT and contains the Iml1p, Npr2p, and Npr3p proteins. Synonyms include IML1 complex and SEACIT complex. The complex acts as a negative regulator of TORC1 by stimulating GTP hydrolysis on Rag GTPases, thereby preventing TORC1 activation under nutrient-poor conditions.
Why Is GATOR1 complex Important in Cell Biology?
The GATOR1 complex is a central negative regulator of mTORC1, one of the most important growth-control pathways in eukaryotes. By acting as a GAP for Rag GTPases, GATOR1 ensures that mTORC1 remains off when nutrients are scarce, preventing inappropriate anabolic activity. Dysregulation of GATOR1 is directly implicated in human disease: germline loss-of-function variants in DEPDC5, NPRL2, and NPRL3 cause focal epilepsies, and somatic mutations in these genes have been linked to cancer and other proliferative disorders [3,4,5]. Additionally, GATOR1 status affects chemotherapy responses, such as cisplatin sensitivity, making it a potential biomarker and therapeutic target. Understanding GATOR1 structure and regulation is therefore essential for both basic cell biology and translational medicine.
• GATOR1 is a key negative regulator of mTORC1, controlling cell growth and metabolism in response to nutrient availability.
• Mutations in GATOR1 genes (DEPDC5, NPRL2, NPRL3) are among the most common causes of focal epilepsies [3,4].
• GATOR1-associated epilepsy often presents with variable phenotypes, including nocturnal frontal lobe epilepsy and other focal seizures.
• GATOR1 activity modulates sensitivity to chemotherapeutic drugs such as cisplatin, linking it to cancer treatment.
• Structural studies of GATOR1 have revealed how it assembles with KICSTOR and SAMTOR into a lysosomal supercomplex.
• GATOR1 regulates the Rheb GTPase pathway, providing crosstalk between amino acid sensing and growth factor signaling.
• mTORC1 auto-regulates TFE3 localization, and GATOR1 loss affects this feedback loop, impacting lysosomal function.
• GATOR1 is a model system for studying GAP complex assembly and Rag GTPase regulation.
• The complex is conserved from yeast to humans, enabling genetic studies in S. cerevisiae (SEACIT).
• GATOR1 variants are being explored as biomarkers for epilepsy surgery outcomes and targeted therapies.
What Happens During GATOR1 complex?
Nutrient sensing and Rag GTPase regulation
In simple terms: GATOR1 acts like a brake on a growth switch when nutrients are low.
Under amino acid or nutrient limitation, the GATOR1 complex localizes to the lysosomal surface and interacts with Rag GTPases. GATOR1 functions as a GTPase-activating protein (GAP) for RagA/B, promoting their GDP-bound state, which prevents mTORC1 activation. This regulation is essential for matching cell growth to nutrient availability. Structural and biochemical studies have shown that GATOR1 specifically stimulates GTP hydrolysis on Rag GTPases, thereby maintaining TORC1 in an inactive state.
Assembly into the lysosomal nutrient-sensing supercomplex
In simple terms: GATOR1 teams up with other proteins on the lysosome to form a nutrient-sensing hub.
GATOR1 does not act alone; it assembles with KICSTOR and SAMTOR into a large lysosomal supercomplex. Recent cryo-EM structures have revealed how KICSTOR-GATOR1-SAMTOR coordinates nutrient signals to control mTORC1. This supercomplex ensures that GATOR1 is properly positioned to regulate Rag GTPases in response to amino acid levels. The assembly is dynamic and involves multiple protein-protein interfaces that are critical for function.
Inhibition of TORC1 signaling
In simple terms: By keeping Rag GTPases off, GATOR1 shuts down the growth-promoting TORC1 pathway.
The ultimate outcome of GATOR1 activity is inhibition of TORC1 (mTORC1 in humans). By converting Rag GTPases to their inactive GDP-bound form, GATOR1 prevents mTORC1 recruitment to the lysosome and its subsequent activation by Rheb. This negative regulation is crucial for preventing uncontrolled cell growth under stress conditions. Loss of GATOR1 function leads to constitutive mTORC1 activation even in nutrient-poor environments.
Crosstalk with Rheb and growth factor signaling
In simple terms: GATOR1 also influences another growth switch called Rheb.
Beyond Rag GTPases, GATOR1 has been implicated in regulating the Rheb GTPase, which directly activates mTORC1. A recent study describes how GATOR1 complex regulates Rheb GTPase, providing a layer of crosstalk between amino acid sensing and growth factor signaling. This suggests that GATOR1 may integrate multiple inputs to fine-tune mTORC1 activity. The exact molecular details of GATOR1-mediated Rheb regulation are an active area of research.
Feedback regulation of TFE3 and lysosomal function
In simple terms: mTORC1 controls its own regulators, and GATOR1 loss affects this feedback.
mTORC1 restricts TFE3 activity by auto-regulating its presence on lysosomes, a process that is influenced by GATOR1 status. When GATOR1 is lost, mTORC1 becomes hyperactive, altering TFE3 localization and lysosomal gene expression. This feedback loop highlights the interconnectedness of nutrient sensing, lysosomal function, and GATOR1. Dysregulation of this axis may contribute to disease phenotypes observed in GATOR1-mutant cells.
Key Genes Involved in GO:1990130 GATOR1 complex
The following genes and proteins are core components or direct regulators of the GATOR1 complex (GO:1990130) and its associated signaling network.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DEPDC5 | Core subunit of GATOR1; acts as a scaffold for the complex | Most frequently mutated GATOR1 gene in focal epilepsies; target for epilepsy genetics [3,4] |
| NPRL2 | Core subunit of GATOR1; essential for GAP activity | Mutations cause focal epilepsy; involved in cisplatin sensitivity [1,3] |
| NPRL3 | Core subunit of GATOR1; stabilizes the complex | Mutations linked to epilepsy and cancer; structural studies [3,8] |
| RagA (RRAGA) | Small GTPase; substrate of GATOR1 GAP activity | Key node in mTORC1 activation; regulated by GATOR1 |
| RagB (RRAGB) | Small GTPase; substrate of GATOR1 GAP activity | Mediates amino acid signaling to mTORC1 |
| RagC (RRAGC) | Small GTPase; partner of RagA/B | Forms heterodimers with RagA/B; regulated by GATOR1 |
| RagD (RRAGD) | Small GTPase; partner of RagA/B | Alternative Rag GTPase; contributes to nutrient sensing |
| mTOR | Kinase; central growth regulator inhibited by GATOR1 | Target of GATOR1-mediated regulation; readout of pathway activity |
| Rheb | GTPase; direct activator of mTORC1 | Regulated by GATOR1 complex; crosstalk with growth factors |
| KICSTOR | Lysosomal scaffold complex; recruits GATOR1 | Part of the KICSTOR-GATOR1-SAMTOR supercomplex |
| SAMTOR | S-adenosylmethionine sensor; interacts with GATOR1 | Links methionine metabolism to mTORC1 via GATOR1 |
| TFE3 | Transcription factor; regulated by mTORC1 and GATOR1 | Readout of lysosomal function and feedback |
| Iml1p (yeast) | Yeast ortholog of DEPDC5; SEACIT subunit | Model for GATOR1 function in S. cerevisiae |
| Npr2p (yeast) | Yeast ortholog of NPRL2; SEACIT subunit | Genetic studies of TORC1 regulation |
| Npr3p (yeast) | Yeast ortholog of NPRL3; SEACIT subunit | Conserved function in nutrient sensing |
| LAMTOR1 | Component of Ragulator; anchors Rag GTPases | Upstream regulator of GATOR1-Rag interaction |
| v-ATPase | Proton pump; required for amino acid sensing | Regulates GATOR1 recruitment to lysosomes |
| SLC38A9 | Lysosomal arginine sensor; modulates GATOR1 | Connects amino acid availability to GATOR1 |
How Is GATOR1 complex Regulated?
GATOR1 complex activity is regulated at multiple levels. Its localization to the lysosome depends on KICSTOR and the Ragulator complex, which are recruited by amino acid signals. The v-ATPase and the arginine sensor SLC38A9 modulate GATOR1 recruitment and activity in response to nutrient levels. Additionally, SAMTOR senses S-adenosylmethionine and interacts with GATOR1 to link methionine metabolism to mTORC1 inhibition. Post-translational modifications and protein-protein interactions further fine-tune GATOR1 function, although the precise mechanisms remain under investigation. mTORC1 itself exerts feedback regulation on TFE3 and lysosomal function, indirectly affecting GATOR1-associated pathways.
GATOR1 complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DEPDC5 | Familial focal epilepsy with variable foci (FFEVF); focal cortical dysplasia | Depdc5 knockout mouse; patient-derived iPSC neurons |
| NPRL2 | Focal epilepsy; cisplatin sensitivity in cancer | NPRL2 knockout cell lines; xenograft models |
| NPRL3 | Focal epilepsy; cancer predisposition | NPRL3 knockout zebrafish; CRISPR knock-in mice |
| RagA/B | mTORC1-related disorders; cancer | RagA/B mutant knock-in cells; organoids |
| TFE3 | Lysosomal storage disorders; cancer | TFE3 reporter cells; GATOR1-deficient models |
GATOR1 complex and focal epilepsies
Germline mutations in DEPDC5, NPRL2, and NPRL3 are major causes of focal epilepsies, including familial focal epilepsy with variable foci (FFEVF) and sporadic focal epilepsy [3,4]. The landscape of GATOR1 variants in epilepsy has been extensively characterized, revealing a wide spectrum of loss-of-function alleles. Clinical features of GATOR1-associated epilepsy include nocturnal frontal lobe seizures and variable age of onset. Genetic testing for GATOR1 genes is now recommended for patients with focal epilepsy of unknown cause.
GATOR1 complex in cancer and chemotherapy response
GATOR1 complex controls cisplatin sensitivity, and loss of GATOR1 components can alter cancer cell responses to this chemotherapeutic agent. This suggests that GATOR1 status could serve as a biomarker for platinum-based therapy. Additionally, somatic mutations in GATOR1 genes have been observed in various cancers, although the full spectrum is still being defined. The mTORC1 hyperactivation caused by GATOR1 loss may promote tumor growth under certain conditions.
GATOR1 complex and lysosomal dysfunction
mTORC1 restricts TFE3 activity by auto-regulating its presence on lysosomes, and GATOR1 loss disrupts this feedback, leading to altered lysosomal function. This may contribute to neurodegeneration or metabolic disorders, although direct evidence in human patients is still emerging. The KICSTOR-GATOR1-SAMTOR supercomplex integrates multiple nutrient signals, and its dysfunction could affect lysosomal homeostasis.
From GATOR1 complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of GATOR1 cause mTORC1 hyperactivation? | DEPDC5 or NPRL2 knockout cell lines (e.g., HEK293T, HeLa) |
| What is the effect of a specific epilepsy-associated point mutation? | CRISPR point-mutation knock-in of DEPDC5 or NPRL3 variants |
| How does GATOR1 localize to the lysosome? | Tagged knock-in of DEPDC5 with GFP or HA; live-cell imaging |
| Can GATOR1 overexpression suppress tumor growth? | Doxycycline-inducible overexpression of NPRL2 in cancer cells |
| What genes are synthetic lethal with GATOR1 loss? | Genome-wide CRISPR library screening in GATOR1-knockout cells |
| How does GATOR1 regulate TFE3 and lysosomal genes? | Transcriptomic and proteomic analysis of GATOR1-knockout cells |
How to Study the GATOR1 complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss of GATOR1 subunit expression | Studying mTORC1 activation and drug sensitivity |
| CRISPR point mutation | Effect of specific patient variants | Modeling epilepsy-associated mutations |
| Knock-in tagging | Subcellular localization of GATOR1 | Live-cell imaging of lysosomal recruitment |
| Overexpression | Gain-of-function effects | Testing tumor suppressor activity |
| CRISPR library screening | Genome-wide modifiers of GATOR1 phenotype | Identifying synthetic lethal partners |
| RNA-seq | Transcriptional changes | Analyzing TFE3 target genes and lysosomal programs |
| Proteomics | Protein interactions and abundance | Mapping the GATOR1 interactome |
| Cryo-EM | High-resolution structure | Understanding GATOR1 assembly and GAP mechanism |
CRISPR knockout and point-mutation models
CRISPR-Cas9 knockout of DEPDC5, NPRL2, or NPRL3 is widely used to study GATOR1 function. Knockout cell lines show constitutive mTORC1 activation and altered nutrient sensing. Point-mutation knock-in models can recapitulate patient-specific variants identified in epilepsy. These models are essential for linking genotype to cellular phenotype.
Biochemical and structural approaches
Recombinant GATOR1 complex can be purified for in vitro GAP assays using Rag GTPases. Cryo-EM has been used to solve the structure of the KICSTOR-GATOR1-SAMTOR supercomplex, revealing molecular details of assembly. These methods provide mechanistic insights into GATOR1 function.
Omics and screening methods
RNA-seq and proteomics can identify transcriptional and proteomic changes upon GATOR1 loss. Genome-wide CRISPR library screening can uncover synthetic lethal interactions and modifiers of GATOR1-dependent phenotypes. These approaches are powerful for discovering new components and therapeutic targets.
Imaging and localization studies
Fluorescence microscopy of tagged GATOR1 subunits (e.g., GFP-DEPDC5) allows visualization of lysosomal recruitment. Live-cell imaging can track dynamic changes in GATOR1 localization in response to nutrients. These methods complement biochemical and genetic approaches.
How CRISPR Can Be Used to Study GO:1990130 GATOR1 complex
Knockout
CRISPR knockout of DEPDC5, NPRL2, or NPRL3 generates GATOR1-deficient cells that exhibit constitutive mTORC1 activity. These models are used to study nutrient sensing, drug resistance, and epilepsy mechanisms [1,3]. Knockout cells can also be used for synthetic lethal screens to identify vulnerabilities.
Point Mutation
Point-mutation knock-in of specific GATOR1 variants (e.g., DEPDC5 missense mutations found in epilepsy patients) allows precise modeling of disease-associated alleles. These models help determine whether a variant is loss-of-function, hypomorphic, or dominant-negative. They are valuable for genotype-phenotype correlation studies.
Knock-in
Knock-in of epitope tags (e.g., GFP, HA) into endogenous GATOR1 genes enables visualization and immunoprecipitation of the complex at physiological expression levels. Tagged knock-in models are useful for studying lysosomal localization and dynamic assembly. They can also be combined with live-cell imaging to track GATOR1 in real time.
Overexpression
Overexpression of GATOR1 subunits (e.g., NPRL2) can suppress mTORC1 signaling and inhibit cell growth. This approach is used to test whether GATOR1 acts as a tumor suppressor and to identify downstream effects. Inducible overexpression systems allow controlled timing and dosage.
How EDITGENE Supports GATOR1 complex Research
Researchers studying GATOR1 complex-related genes often need to determine whether a candidate gene is causally involved in mTORC1 regulation, epilepsy, or cancer. EDITGENE provides a comprehensive suite of CRISPR-based services to create precisely engineered cell and animal models, enabling functional validation of GATOR1 components and their variants.
Contact EDITGENE today to design your custom CRISPR model for GATOR1 complex research.
Frequently Asked Questions About GATOR1 complex
What is the GATOR1 complex?
The GATOR1 complex (GO:1990130) is a GTPase-activating protein (GAP) complex that regulates TORC1 signaling by interacting with the Rag GTPase. In humans, it consists of DEPDC5, NPRL2, and NPRL3.
What genes are involved in the GATOR1 complex?
The core human genes are DEPDC5, NPRL2, and NPRL3. In S. cerevisiae, the orthologous SEACIT complex contains Iml1p, Npr2p, and Npr3p.
What is the function of GATOR1?
GATOR1 acts as a GAP for Rag GTPases, promoting their inactive GDP-bound state and thereby inhibiting mTORC1 signaling under nutrient-poor conditions.
How is GATOR1 related to epilepsy?
Germline mutations in DEPDC5, NPRL2, and NPRL3 are major causes of focal epilepsies, including familial focal epilepsy with variable foci (FFEVF) [3,4,5].
What diseases are associated with GATOR1 mutations?
GATOR1 mutations are linked to focal epilepsies, focal cortical dysplasia, and altered chemotherapy responses in cancer [1,3,5].
How does GATOR1 regulate mTORC1?
GATOR1 stimulates GTP hydrolysis on RagA/B, preventing mTORC1 recruitment to the lysosome and its activation by Rheb.
What is the structure of the GATOR1 complex?
GATOR1 is a heterotrimer of DEPDC5, NPRL2, and NPRL3. It assembles with KICSTOR and SAMTOR into a lysosomal supercomplex.
Can GATOR1 be targeted for cancer therapy?
GATOR1 status affects cisplatin sensitivity, suggesting it could be a biomarker for platinum-based therapy. However, direct targeting requires further research.
What model systems are used to study GATOR1?
Common models include CRISPR knockout cell lines, patient-derived iPSCs, mouse models, and S. cerevisiae (SEACIT) [2,3].
How can I create a GATOR1 knockout cell line?
EDITGENE provides custom CRISPR knockout services for DEPDC5, NPRL2, NPRL3, and related genes. Contact us for a quote.
Conclusion
The GATOR1 complex (GO:1990130) is a critical regulator of mTORC1 signaling, acting as a GAP for Rag GTPases to inhibit cell growth under nutrient-poor conditions. Its dysfunction is directly linked to focal epilepsies and influences cancer chemotherapy responses [1,3,4,5]. Recent structural and biochemical studies have revealed how GATOR1 assembles into a lysosomal supercomplex with KICSTOR and SAMTOR, providing a framework for understanding nutrient sensing. Continued research using CRISPR models will further elucidate GATOR1 biology and its potential as a therapeutic target.
References
- 1. Pan Z et al.. 2025. GATOR1 complex controls cisplatin sensitivity.. Cell Death Dis 17(1):58 PMID: 41469472
- 2. Ivanova I et al.. 2024. Structures and Functions of the Human GATOR1 Complex.. Subcell Biochem 104:269-294 PMID: 38963491
- 3. Baldassari S et al.. 2019. The landscape of epilepsy-related GATOR1 variants.. Genet Med 21(2):398-408 PMID: 30093711
- 4. Baldassari S et al.. 2016. GATOR1 complex: the common genetic actor in focal epilepsies.. J Med Genet 53(8):503-10 PMID: 27208208
- 5. Yin K et al.. 2023. Clinical and genetic features of GATOR1 complex-associated epilepsy.. J Med Genet 60(8):784-790 PMID: 36604176
- 6. Prabhakar A et al.. 2025. Regulation of the Rheb GTPase via GATOR1 Complex.. bioRxiv PMID: 41509360
- 7. Zwakenberg S et al.. 2024. mTORC1 restricts TFE3 activity by auto-regulating its presence on lysosomes.. Mol Cell 84(22):4368-4384.e6 PMID: 39486419
- 8. Lupton CJ et al.. 2026. Structure of the lysosomal KICSTOR-GATOR1-SAMTOR nutrient-sensing supercomplex.. Cell 189(4):1185-1200.e28 PMID: 41512879
