GO:0090459 intracellular aspartate homeostasis: Metabolic Regulation, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0090459 (intracellular aspartate homeostasis) describes the biological process that maintains a steady-state level of aspartate inside a cell, as defined by QuickGO.
• Aspartate is a non-essential amino acid that feeds the malate-aspartate shuttle, the urea cycle, nucleotide biosynthesis, and the aspartate-argininosuccinate shunt, linking mitochondrial and cytosolic metabolism.
• Key genes and proteins implicated in aspartate homeostasis include GOT1, GOT2, MDH1, MDH2, SLC25A12 (Aralar), SLC25A13, ASS1, ASL, and CRMP2 (DPYSL2).
• Disruption of aspartate homeostasis is observed in pancreatic cancer, gastric cancer, Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis models.
• CRISPR knockout, point-mutation, knock-in, and overexpression cell models enable causal testing of genes controlling intracellular aspartate levels.
• Biosensors, metabolomics, and CRISPR library screening are core methods for dissecting aspartate homeostasis in health and disease.
Description
Intracellular aspartate homeostasis (GO:0090459) is the biological process that maintains a steady-state level of aspartate within a cell, as defined by the Gene Ontology resource QuickGO. Aspartate is a non-essential amino acid that participates in the malate-aspartate shuttle, the urea cycle, nucleotide biosynthesis, and the aspartate-argininosuccinate shunt, making its intracellular concentration a central node in cellular metabolism. Because aspartate is both a substrate and a product of multiple compartmentalized reactions, its homeostasis requires coordinated transport and enzymatic interconversion across the cytosol and mitochondria. Researchers study GO:0090459 because perturbations in aspartate levels are linked to cancer metabolism, neurodegenerative disease, and mitochondrial dysfunction. For example, KRAS-driven pancreatic cancer cells depend on a glutamine-fueled pathway that converges on aspartate synthesis and the malate-aspartate shuttle. In neurons, the mitochondrial aspartate-glutamate carrier Aralar (SLC25A12) influences GABA sequestration and social behavior, tying aspartate homeostasis to mitochondrial and synaptic function. In Parkinson's disease models, L-ornithine L-aspartate restores mitochondrial function and modulates intracellular calcium homeostasis, indicating that aspartate availability can affect neuronal survival. This article integrates the QuickGO definition of GO:0090459 with verified PubMed literature to summarize the mechanisms, key genes, disease links, and experimental methods used to study intracellular aspartate homeostasis. It is intended for researchers designing CRISPR-based cell models and functional genomics screens targeting aspartate metabolism.
intracellular aspartate homeostasis At A Glance
| GO ID | GO:0090459 |
|---|---|
| GO term | intracellular aspartate homeostasis |
| Ontology | biological_process |
| Synonym | aspartate homeostasis; cellular aspartate homeostasis |
| Definition | A homeostatic process involved in the maintenance of a steady state level of aspartate within a cell. |
| Major function | Maintains intracellular aspartate levels for the malate-aspartate shuttle, urea cycle, nucleotide biosynthesis, and neurotransmission. |
| Key compartments | Cytosol and mitochondria |
| Representative genes | GOT1, GOT2, MDH1, MDH2, SLC25A12, SLC25A13, ASS1, ASL, DPYSL2 (CRMP2) |
| Related pathways | Malate-aspartate shuttle, aspartate-argininosuccinate shunt, glutamine metabolism, urea cycle |
What Is GO:0090459?
GO:0090459 (intracellular aspartate homeostasis) is a biological process defined by QuickGO as the homeostatic process involved in the maintenance of a steady state level of aspartate within a cell. In other words, it encompasses all cellular mechanisms that sense, buffer, and adjust the concentration of free aspartate so that it remains within a functional range despite changes in nutrient supply, metabolic demand, or mitochondrial activity. This process includes enzymatic interconversion of aspartate with oxaloacetate and glutamate, transport of aspartate and its precursors across mitochondrial and plasma membranes, and integration with pathways such as the malate-aspartate shuttle and the urea cycle.
Why Is intracellular aspartate homeostasis Important in Cell Biology?
Intracellular aspartate homeostasis is important because aspartate sits at the intersection of nitrogen disposal, redox balance, and biosynthetic supply. The malate-aspartate shuttle depends on aspartate and glutamate exchange to transfer reducing equivalents into mitochondria, and its activity influences NAD+/NADH ratios and mitochondrial function. In cancer, aspartate availability supports nucleotide synthesis and cell proliferation, and KRAS-regulated glutamine metabolism converges on aspartate production through GOT1. In the nervous system, aspartate and its transporters contribute to synaptic signaling and mitochondrial calcium handling, and their dysregulation has been implicated in Parkinson's disease, Alzheimer's disease, and ALS models. Consequently, understanding GO:0090459 is essential for interpreting metabolic phenotypes and for designing targeted CRISPR models.
• Aspartate is a substrate for the malate-aspartate shuttle, which maintains cytosolic and mitochondrial NAD+/NADH balance.
• Aspartate is required for nucleotide biosynthesis and supports proliferation in KRAS-driven pancreatic cancer.
• The mitochondrial aspartate-glutamate carrier Aralar (SLC25A12) influences GABA sequestration and social behavior in mice.
• L-ornithine L-aspartate restores mitochondrial function and modulates intracellular calcium homeostasis in Parkinson's disease models.
• CRMP2 (DPYSL2) coordinates synaptic signaling and is linked to cytoskeletal and metabolic regulation in neurons.
• Amino acid metabolic enzymes, including aspartate-related enzymes, are implicated in gastric cancer tumorigenesis and progression.
• BAG3-mediated BACE1 stabilization and amyloid pathology in Alzheimer's disease models intersect with metabolic stress pathways.
• ALS-causing SOD1 mutations induce amyloid fibril structures and ferroptosis, a process sensitive to metabolic and redox balance.
• Aspartate homeostasis is a tractable target for CRISPR knockout, knock-in, and overexpression studies in cancer and neuronal cell models.
• Biosensors and metabolomics enable real-time or quantitative assessment of aspartate-related metabolic states.
What Happens During intracellular aspartate homeostasis?
Aspartate synthesis and interconversion
In simple terms: The cell makes and recycles aspartate by swapping chemical groups between aspartate, glutamate, and oxaloacetate.
Intracellular aspartate levels are maintained in part by reversible transamination reactions. Cytosolic GOT1 and mitochondrial GOT2 interconvert aspartate and oxaloacetate with glutamate and alpha-ketoglutarate, coupling aspartate homeostasis to the malate-aspartate shuttle. In KRAS-driven pancreatic cancer, glutamine-derived glutamate is converted to alpha-ketoglutarate and then to oxaloacetate, which is transaminated by GOT1 to produce aspartate, supporting redox balance and proliferation. These reactions ensure that aspartate can be generated or consumed according to metabolic demand.
Mitochondrial transport and the malate-aspartate shuttle
In simple terms: Mitochondria and the cytosol exchange aspartate and related molecules to keep energy metabolism running.
The malate-aspartate shuttle requires aspartate and glutamate exchange across the mitochondrial inner membrane, mediated by carriers such as Aralar (SLC25A12) and citrin (SLC25A13). Aralar sequesters GABA into hyperactive mitochondria and its loss causes social behavior deficits, demonstrating that mitochondrial aspartate-glutamate exchange influences neurotransmitter handling and behavior. The shuttle also contributes to maintaining NAD+/NADH ratios, which can be monitored with genetically encoded biosensors.
Aspartate in the urea cycle and argininosuccinate shunt
In simple terms: Aspartate helps the cell dispose of nitrogen and recycle amino acids.
Aspartate is a nitrogen donor in the urea cycle, where argininosuccinate synthetase (ASS1) and argininosuccinate lyase (ASL) use aspartate to form argininosuccinate and then arginine and fumarate. This connects intracellular aspartate homeostasis to nitrogen disposal and to the aspartate-argininosuccinate shunt, which links the urea cycle with the tricarboxylic acid cycle. Because these reactions consume aspartate, their activity can shift the intracellular aspartate pool and influence biosynthetic pathways.
Aspartate in neuronal signaling and calcium homeostasis
In simple terms: In neurons, aspartate-related metabolism affects signaling and calcium balance.
Aspartate and its metabolic partners influence synaptic signaling and mitochondrial calcium handling. CRMP2 (DPYSL2) coordinates synaptic signaling and is regulated by phosphorylation, linking cytoskeletal dynamics to neuronal metabolism. In Parkinson's disease models, L-ornithine L-aspartate restores mitochondrial function and modulates intracellular calcium homeostasis, suggesting that aspartate availability can affect neuronal survival. These observations place GO:0090459 within the broader context of neuro-metabolic regulation.
Integration with redox and biosynthetic networks
In simple terms: Aspartate levels are tied to the cell's redox state and its ability to build new molecules.
Aspartate homeostasis is integrated with redox balance and biosynthesis. The malate-aspartate shuttle helps maintain NAD+/NADH ratios, and biosensors for these ratios can report on shuttle activity. Aspartate is also a precursor for nucleotide biosynthesis, and its availability supports proliferation in cancer cells. Amino acid metabolic enzymes, including those involved in aspartate metabolism, contribute to tumorigenesis and progression in gastric cancer. Thus, aspartate homeostasis is a hub that connects energy metabolism, redox control, and biosynthetic capacity.
Key Genes Involved in GO:0090459 intracellular aspartate homeostasis
The following genes and proteins are experimentally implicated in intracellular aspartate homeostasis, mitochondrial transport, and related metabolic or neuronal processes.
| Gene | Major Role | Research Relevance |
|---|---|---|
| GOT1 | Cytosolic aspartate aminotransferase; interconverts aspartate and oxaloacetate | KRAS-regulated glutamine metabolism and redox balance in pancreatic cancer |
| GOT2 | Mitochondrial aspartate aminotransferase; supports malate-aspartate shuttle | Mitochondrial aspartate metabolism and NAD+/NADH balance |
| MDH1 | Cytosolic malate dehydrogenase; part of malate-aspartate shuttle | Redox shuttling and aspartate-linked metabolism |
| MDH2 | Mitochondrial malate dehydrogenase; part of malate-aspartate shuttle | Mitochondrial redox and aspartate homeostasis |
| SLC25A12 (Aralar) | Mitochondrial aspartate-glutamate carrier | GABA sequestration, social behavior, and mitochondrial function |
| SLC25A13 (Citrin) | Mitochondrial aspartate-glutamate carrier | Aspartate transport and urea cycle-related metabolism |
| ASS1 | Argininosuccinate synthetase; uses aspartate in urea cycle | Nitrogen disposal and aspartate-argininosuccinate shunt |
| ASL | Argininosuccinate lyase; releases arginine and fumarate | Urea cycle and aspartate consumption |
| DPYSL2 (CRMP2) | Neuronal phosphoprotein coordinating synaptic signaling | Synaptic signaling and neuronal metabolism |
| BAG3 | Co-chaperone involved in protein quality control | Alzheimer's disease neuropathology and metabolic stress |
| BACE1 | Beta-secretase; amyloid precursor protein processing | Alzheimer's disease amyloid pathology |
| SOD1 | Cu/Zn superoxide dismutase; antioxidant enzyme | ALS-causing mutations, amyloid fibrils, and ferroptosis |
| KRAS | Small GTPase driving proliferation and metabolic reprogramming | Glutamine-dependent aspartate synthesis in pancreatic cancer |
| GLS | Glutaminase; converts glutamine to glutamate | Upstream of aspartate synthesis in cancer |
| SLC1A3 (EAAT1) | Glutamate/aspartate transporter | Neuronal and glial amino acid transport |
| SLC1A2 (EAAT2) | Glutamate/aspartate transporter | Synaptic signaling and amino acid homeostasis |
| NADH/NAD+ biosensors | Genetically encoded reporters of redox state | Monitoring malate-aspartate shuttle activity |
How Is intracellular aspartate homeostasis Regulated?
Intracellular aspartate homeostasis is regulated by the availability of glutamine and glutamate, by the activity of transaminases such as GOT1 and GOT2, and by mitochondrial carriers including SLC25A12 and SLC25A13. In KRAS-driven cancer, glutamine metabolism is reprogrammed to support aspartate synthesis and redox balance, linking oncogenic signaling to aspartate homeostasis. Mitochondrial calcium and energy status can also influence the malate-aspartate shuttle, and biosensors for NAD+/NADH ratios provide readouts of this regulation. In neurons, proteins such as CRMP2 coordinate synaptic signaling with metabolic state, and L-ornithine L-aspartate can modulate mitochondrial function and calcium homeostasis in disease models.
intracellular aspartate homeostasis and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| GOT1 | Pancreatic cancer metabolism and redox balance | CRISPR knockout in pancreatic cancer cell lines |
| SLC25A12 (Aralar) | Mitochondrial dysfunction and social behavior deficits | Knockout mouse or neuronal cell model |
| DPYSL2 (CRMP2) | Synaptic signaling and neuronal metabolism | Point-mutation or knockout neuronal cells |
| BAG3 | Alzheimer's disease neuropathology | Knockout or knock-in in neuronal models |
| SOD1 | ALS and ferroptosis | Point-mutation knock-in in motor neuron models |
Cancer metabolism and aspartate dependence
KRAS-driven pancreatic cancer cells rely on a glutamine-fueled pathway that produces aspartate through GOT1, supporting redox balance and proliferation. Amino acid metabolic enzymes, including aspartate-related enzymes, are also implicated in gastric cancer tumorigenesis and progression. These findings suggest that intracellular aspartate homeostasis is a metabolic vulnerability in certain cancers and a candidate target for CRISPR-based functional studies.
Neurodegeneration and mitochondrial dysfunction
In Parkinson's disease models, L-ornithine L-aspartate restores mitochondrial function and modulates intracellular calcium homeostasis, indicating that aspartate availability influences neuronal survival. Aralar (SLC25A12) sequesters GABA into hyperactive mitochondria and its disruption causes social behavior deficits, linking mitochondrial aspartate-glutamate exchange to neuronal function. CRMP2 coordinates synaptic signaling and is relevant to neuronal metabolism. In Alzheimer's disease models, BAG3-mediated BACE1 stabilization affects neuropathology and memory deficits. In ALS, SOD1 mutations induce amyloid fibril structures and ferroptosis, a process sensitive to metabolic and redox balance.
Mitochondrial and metabolic disorders
The malate-aspartate shuttle and mitochondrial aspartate-glutamate carriers are central to intracellular aspartate homeostasis, and their dysfunction can affect NAD+/NADH balance and mitochondrial function. Biosensors for NAD+/NADH ratios enable researchers to monitor these changes in live cells. Because aspartate is also a nitrogen donor in the urea cycle, perturbations in aspartate homeostasis may intersect with disorders of nitrogen disposal.
From intracellular aspartate homeostasis-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of GOT1 alter intracellular aspartate levels and proliferation? | CRISPR knockout in cancer cell lines |
| Does a point mutation in SLC25A12 affect mitochondrial aspartate transport? | Point-mutation knock-in in neuronal cells |
| Can tagged GOT2 report mitochondrial aspartate metabolism? | Tagged knock-in with fluorescent or affinity tag |
| Does overexpression of CRMP2 change synaptic signaling? | Overexpression in neuronal cultures |
| Does mutant SOD1 induce ferroptosis via metabolic stress? | Point-mutation knock-in in motor neurons |
| Can a CRISPR library screen identify regulators of aspartate homeostasis? | Genome-wide CRISPR knockout library screening |
How to Study the intracellular aspartate homeostasis Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Genetically encoded NAD+/NADH biosensors | Cytosolic and mitochondrial redox ratios | Monitoring malate-aspartate shuttle activity |
| Metabolomics | Aspartate and related metabolite levels | Quantifying intracellular aspartate homeostasis |
| Stable isotope tracing | Flux through aspartate-producing pathways | Glutamine-dependent aspartate synthesis in cancer |
| CRISPR knockout screening | Gene essentiality and metabolic dependencies | Identifying regulators of aspartate homeostasis |
| Western blotting | Protein expression of GOT1, GOT2, CRMP2, etc. | Validating CRISPR perturbations |
| Immunofluorescence | Subcellular localization of metabolic enzymes | Assessing mitochondrial and cytosolic distribution |
| Calcium imaging | Intracellular calcium dynamics | Neuronal models treated with L-ornithine L-aspartate |
| Behavioral assays | Social behavior and neurological phenotypes | Aralar knockout models |
Genetically encoded biosensors for redox and metabolism
Genetically encoded biosensors can evaluate NAD+/NADH ratios in cytosolic and mitochondrial compartments, providing a readout of malate-aspartate shuttle activity that is linked to aspartate homeostasis. These tools allow real-time monitoring of metabolic changes in live cells and can be combined with CRISPR perturbations.
Metabolomics and stable isotope tracing
Metabolomics and isotope tracing can quantify aspartate and related metabolites such as glutamate, oxaloacetate, and malate. In pancreatic cancer, glutamine tracing revealed a KRAS-regulated pathway that produces aspartate through GOT1. Similar approaches can be applied to gastric cancer models to study amino acid metabolic enzymes.
CRISPR screening and functional genomics
CRISPR library screening enables unbiased identification of genes that regulate intracellular aspartate homeostasis. Genome-wide knockout screens can be coupled with metabolite measurements or biosensor readouts to discover modulators of aspartate metabolism. Bioinformatics analysis of screen data helps prioritize candidate genes for validation.
Neuronal and mitochondrial assays
Neuronal models can be used to study aspartate-related mitochondrial function and calcium homeostasis. L-ornithine L-aspartate treatment in Parkinson's disease models restored mitochondrial function and modulated intracellular calcium. Aralar (SLC25A12) knockout or knockdown models can reveal effects on GABA sequestration and behavior. CRMP2 phosphorylation and synaptic signaling can be assessed in neuronal cultures.
How CRISPR Can Be Used to Study GO:0090459 intracellular aspartate homeostasis
Knockout
CRISPR knockout of genes such as GOT1, GOT2, or SLC25A12 can test their causal role in intracellular aspartate homeostasis. For example, knockout of GOT1 in pancreatic cancer cells can reveal effects on aspartate production and proliferation. Knockout of Aralar (SLC25A12) in neuronal models can assess mitochondrial GABA sequestration and behavior.
Point Mutation
Point-mutation knock-in can model disease-associated variants in genes related to aspartate homeostasis. For instance, ALS-causing SOD1 mutations can be introduced to study amyloid fibril structures and ferroptosis. Point mutations in CRMP2 (DPYSL2) can be used to dissect phosphorylation-dependent synaptic signaling.
Knock-in
Knock-in of tagged versions of metabolic enzymes, such as GOT2 or MDH2, enables visualization and affinity purification of these proteins. Tagged knock-in models can be combined with biosensors to monitor NAD+/NADH ratios and aspartate-related metabolism. Knock-in of disease variants in BAG3 or SOD1 can model Alzheimer's disease or ALS pathology.
Overexpression
Overexpression of genes such as CRMP2 or GOT1 can test gain-of-function effects on synaptic signaling and aspartate metabolism. Overexpression models are useful for validating whether increased aspartate production or transport alters cellular phenotypes. These models can be paired with metabolomics and biosensor readouts.
How EDITGENE Supports intracellular aspartate homeostasis Research
Researchers studying intracellular aspartate homeostasis-related genes often need to determine whether a candidate gene is causally involved in maintaining aspartate levels, whether a disease-associated variant alters metabolic function, or whether overexpression is sufficient to change cellular phenotypes. EDITGENE provides CRISPR-based cell model services that enable these causal experiments in relevant cancer and neuronal cell backgrounds.
Contact EDITGENE today to design your custom CRISPR model for intracellular aspartate homeostasis research.
Frequently Asked Questions About intracellular aspartate homeostasis
What is intracellular aspartate homeostasis (GO:0090459)?
GO:0090459 is a biological process defined by QuickGO as the homeostatic process involved in the maintenance of a steady state level of aspartate within a cell. It includes enzymatic interconversion, transport, and integration with pathways such as the malate-aspartate shuttle and urea cycle.
What genes are involved in intracellular aspartate homeostasis?
Key genes include GOT1, GOT2, MDH1, MDH2, SLC25A12 (Aralar), SLC25A13 (Citrin), ASS1, ASL, and DPYSL2 (CRMP2).
Why is aspartate important for cancer metabolism?
Aspartate supports nucleotide biosynthesis and redox balance. In KRAS-driven pancreatic cancer, glutamine metabolism produces aspartate through GOT1 to support proliferation. Amino acid metabolic enzymes are also implicated in gastric cancer.
How is intracellular aspartate homeostasis studied?
Researchers use genetically encoded biosensors for NAD+/NADH ratios, metabolomics, stable isotope tracing, CRISPR screening, and neuronal assays.
What is the role of SLC25A12 (Aralar) in aspartate homeostasis?
Aralar is a mitochondrial aspartate-glutamate carrier. Its dysfunction causes GABA sequestration into hyperactive mitochondria and social behavior deficits in mice.
Can CRISPR knockout be used to study aspartate homeostasis?
Yes. CRISPR knockout of GOT1, GOT2, or SLC25A12 can test their causal roles in aspartate production, mitochondrial transport, and cellular phenotypes.
What diseases are linked to aspartate homeostasis?
Aspartate homeostasis has been linked to pancreatic cancer, gastric cancer, Parkinson's disease, Alzheimer's disease, and ALS models.
What is the malate-aspartate shuttle?
The malate-aspartate shuttle transfers reducing equivalents between cytosol and mitochondria using aspartate and glutamate exchange, helping maintain NAD+/NADH balance.
How does L-ornithine L-aspartate affect neurons?
In Parkinson's disease models, L-ornithine L-aspartate restores mitochondrial function and modulates intracellular calcium homeostasis.
What CRISPR models are available for aspartate homeostasis research?
EDITGENE provides knockout, point-mutation, knock-in, tagged knock-in, overexpression, and CRISPR library screening models for genes such as GOT1, GOT2, SLC25A12, CRMP2, and SOD1.
Conclusion
Intracellular aspartate homeostasis (GO:0090459) is a central metabolic process that maintains aspartate levels for the malate-aspartate shuttle, urea cycle, nucleotide biosynthesis, and neuronal signaling. Its dysregulation is implicated in cancer, neurodegeneration, and mitochondrial disorders, making it a compelling target for functional genomics and CRISPR-based cell modeling. By combining QuickGO-defined ontology with verified literature, researchers can design rigorous experiments using knockout, point-mutation, knock-in, and overexpression models, supported by biosensors, metabolomics, and CRISPR screening. EDITGENE offers integrated services to accelerate discovery in this field.
References
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