GO:0015800 acidic amino acid transport: Transport Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0015800 (acidic amino acid transport) describes the directed movement of acidic amino acids such as glutamate and aspartate into, out of, or within a cell, or between cells, via transporters or pores.
• Excitatory amino acid transporters (EAATs/SLC1A family) mediate coupled transport of acidic amino acids and also exhibit an anion conduction pathway.
• Vesicular transport of excitatory amino acids is carried out by proteins such as human sialin, which is functionally characterized as a vesicular excitatory amino acid transporter.
• Acidic amino acid transport is essential for neurotransmitter homeostasis, nitrogen metabolism, and cellular pH regulation, and its dysfunction is linked to neurological and metabolic disorders.
• Transport activity can be modulated by substrate availability and by the ionic and sialic acid environment of the membrane.
• CRISPR-based knockout, point-mutation, knock-in, and overexpression models enable causal interrogation of acidic amino acid transporter genes in disease and physiology.
Description
Acidic amino acid transport (GO:0015800) is the biological process by which acidic amino acids, defined as amino acids with a pH below 7, are moved into, out of, or within a cell, or between cells, through transporters or pores. This process is fundamental to cellular physiology because acidic amino acids such as glutamate and aspartate serve dual roles as proteinogenic amino acids and as excitatory neurotransmitters. The directed movement of these molecules across membranes is therefore tightly linked to nitrogen metabolism, synaptic signaling, and ionic homeostasis. Researchers study GO:0015800 to understand how cells acquire and redistribute acidic amino acids, how transport defects contribute to disease, and how transporter activity can be experimentally manipulated. The process is mediated by a diverse set of membrane proteins, including excitatory amino acid transporters (EAATs) and vesicular transporters such as sialin. Because acidic amino acid transport sits at the intersection of metabolism and neurotransmission, it is a recurring target in neurobiology, cancer metabolism, and metabolic engineering research.
acidic amino acid transport At A Glance
| GO ID | GO:0015800 |
|---|---|
| GO term | acidic amino acid transport |
| Ontology | biological_process |
| Synonym | none |
| Major function | Directed movement of acidic amino acids (pH below 7) into, out of, or within cells, or between cells, via transporters or pores |
| Representative transporters | Excitatory amino acid transporters (EAATs/SLC1A family), vesicular excitatory amino acid transporter sialin |
| Substrates | Glutamate, aspartate, and other acidic amino acids |
| Cellular contexts | Plasma membrane uptake, synaptic vesicle loading, intestinal brush-border absorption, vacuolar transport |
| Related processes | Neurotransmission, nitrogen metabolism, ionic homeostasis |
What Is GO:0015800?
According to the Gene Ontology, GO:0015800 (acidic amino acid transport) is defined as the directed movement of acidic amino acids, amino acids with a pH below 7, into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore. In practice, this covers the translocation of glutamate, aspartate, and related acidic amino acids across plasma and organellar membranes, whether by coupled transporters or by channels/pores.
Why Is acidic amino acid transport Important in Cell Biology?
Acidic amino acid transport is important because it controls the availability of glutamate and aspartate for both metabolism and signaling, and because defects in this process are associated with neurological and metabolic dysfunction. The transport of acidic amino acids across the plasma membrane and into organelles determines neurotransmitter pools, supports nitrogen assimilation, and contributes to ionic balance. Because many transporters for acidic amino acids are coupled to ion gradients and can also conduct anions, they represent mechanistically rich systems for studying membrane protein function. Understanding GO:0015800 therefore has direct implications for neurobiology, metabolic disease, and the development of transporter-targeted experimental models.
• Controls synaptic glutamate and aspartate levels, which are central to excitatory neurotransmission.
• Supports nitrogen metabolism and amino acid utilization in microorganisms and mammalian cells.
• Mediates intestinal absorption of acidic amino acids via brush-border membrane transporters.
• Enables vesicular storage of excitatory amino acids through transporters such as sialin.
• Contributes to ionic and pH homeostasis because transport is often coupled to ion gradients.
• Provides a mechanistic model for studying coupled transport and anion conduction in membrane proteins.
• Is modulated by substrate availability and membrane environment, including sialic acid.
• Represents a target for CRISPR-based functional genomics of transporter genes.
• Links to disease biology in neurology and metabolism through transporter dysfunction.
• Offers opportunities for metabolic engineering and transporter characterization in model organisms.
What Happens During acidic amino acid transport?
Substrate recognition and binding
In simple terms: The transporter first recognizes and grabs the acidic amino acid it will move.
Acidic amino acid transport begins with substrate recognition by a membrane transporter or pore. Excitatory amino acid transporters (EAATs) bind glutamate and aspartate with high specificity, and structural and functional studies have defined the molecular basis of this coupled transport. The substrate-binding step is selective for acidic amino acids, consistent with the GO definition of movement of amino acids with a pH below 7.
Coupled translocation across the membrane
In simple terms: The transporter then carries the amino acid across the membrane while moving ions at the same time.
After binding, the transporter undergoes conformational changes that translocate the acidic amino acid across the membrane. EAATs operate as coupled transporters, using ion gradients to drive substrate movement, and they also possess an anion conduction pathway. This coupling means that acidic amino acid transport is energetically linked to the ionic environment of the cell.
Vesicular loading of excitatory amino acids
In simple terms: Inside the cell, acidic amino acids can be packed into vesicles for later release.
Beyond the plasma membrane, acidic amino acids are transported into intracellular organelles. Human sialin has been functionally characterized as a vesicular excitatory amino acid transporter, mediating the uptake of acidic amino acids into vesicles. This vesicular transport step is essential for storing and releasing excitatory amino acids in a regulated manner.
Epithelial and brush-border absorption
In simple terms: In the gut, acidic amino acids are taken up across the intestinal surface.
Acidic amino acid transport also occurs in epithelial tissues. Transport of acidic amino acids by human jejunal brush-border membrane vesicles has been demonstrated, showing that the intestinal epithelium is a site of acidic amino acid absorption. This reflects the broader physiological role of GO:0015800 in nutrient handling.
Microbial and vacuolar acidic amino acid transport
In simple terms: Even yeast and other microbes move acidic amino acids around their cells and vacuoles.
In microorganisms, acidic amino acid transport supports nitrogen-starved cells, and dedicated transporter families mediate bidirectional vacuolar amino acid transport. These systems show that GO:0015800 is evolutionarily conserved and can be studied in genetically tractable models.
Modulation by substrate and membrane environment
In simple terms: How much amino acid is moved can change depending on conditions and the membrane itself.
Transport activity is not fixed. Amino-acid-dependent modulation of amino acid transport has been observed in Xenopus laevis oocytes, indicating that substrate availability can regulate transport. In addition, sialic acid plays a role in synaptosomal transport of amino acid transmitters, linking membrane composition to transport function.
Key Genes Involved in GO:0015800 acidic amino acid transport
The following genes and proteins are experimentally linked to acidic amino acid transport (GO:0015800) and its regulation.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SLC1A1 (EAAT3) | Excitatory amino acid transporter mediating coupled acidic amino acid transport | Model for studying coupled transport and anion conduction |
| SLC1A2 (EAAT2) | Glial excitatory amino acid transporter for glutamate uptake | Key target in neurotransmission and neuroprotection studies |
| SLC1A3 (EAAT1) | Excitatory amino acid transporter in glia | Studied for substrate specificity and ion coupling |
| SLC17A5 (sialin) | Vesicular excitatory amino acid transporter | Functional model for vesicular acidic amino acid transport |
| SLC36A1 | Proton-coupled amino acid transporter | Studied in the context of anionic and cationic amino acid transport concepts |
| SLC7A11 | Cystine/glutamate exchange linked to acidic amino acid flux | Relevant to redox and metabolic studies |
| SLC25A12 | Mitochondrial aspartate/glutamate carrier | Model for organellar acidic amino acid transport |
| SLC25A13 | Mitochondrial aspartate/glutamate carrier | Studied in nitrogen and energy metabolism |
| GOT1 | Aspartate aminotransferase linked to acidic amino acid metabolism | Used in metabolic flux studies |
| GOT2 | Mitochondrial aspartate aminotransferase | Relevant to nitrogen-starved cell models |
| AVT1 | Yeast vacuolar amino acid transporter | Genetic model for bidirectional vacuolar transport |
| AVT3 | Yeast vacuolar amino acid transporter | Used to study transporter family function |
| AVT4 | Yeast vacuolar amino acid transporter | Model for vacuolar acidic amino acid handling |
| SLC1A6 (EAAT4) | Excitatory amino acid transporter | Studied for transport and anion conduction |
| SLC1A7 (EAAT5) | Excitatory amino acid transporter | Model for coupled transport mechanisms |
| GAD1 | Glutamate decarboxylase affecting acidic amino acid pools | Used in metabolic and nitrogen studies |
| GLT1 | Glutamate transporter homolog in model systems | Comparative transporter research |
How Is acidic amino acid transport Regulated?
Acidic amino acid transport is regulated at multiple levels. Transport activity can be modulated by amino acid availability, as shown in Xenopus laevis oocytes where amino-acid-dependent modulation of transport was observed. The membrane environment also matters: sialic acid contributes to synaptosomal transport of amino acid transmitters, indicating that glycosylation and membrane composition influence transport. In addition, the coupling of transport to ion gradients means that changes in ionic conditions directly affect the rate and direction of acidic amino acid movement. In microorganisms, nitrogen starvation alters amino acid transport and metabolism, providing an environmental regulatory axis. Vacuolar transporter families further show that compartmentalization is a regulated feature of acidic amino acid transport.
acidic amino acid transport and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC1A2 (EAAT2) | Excitatory amino acid imbalance in neurological dysfunction | Knockout and point-mutation cell models |
| SLC17A5 (sialin) | Vesicular excitatory amino acid transport defects | Knock-in and overexpression models |
| SLC25A12 | Mitochondrial acidic amino acid transport in metabolism | Knockout metabolic cell models |
| SLC7A11 | Redox and metabolic stress linked to acidic amino acid flux | Overexpression and knockout models |
| AVT1/AVT3 | Vacuolar amino acid transport in yeast models | Yeast knockout and tagged knock-in models |
Neurological dysfunction and excitatory amino acid imbalance
Because acidic amino acids such as glutamate are excitatory neurotransmitters, altered transport can disturb synaptic signaling. Excitatory amino acid transporters mediate coupled transport and anion conduction, and their dysfunction is mechanistically linked to neurological disease processes. Vesicular transport by sialin further highlights how defects in acidic amino acid storage can affect neuronal function.
Metabolic and nitrogen-handling disorders
Acidic amino acid transport is tied to nitrogen metabolism and amino acid utilization. Studies in nitrogen-starved yeast show that transport and metabolism of amino acids are coordinated, providing a model for understanding metabolic disorders. Mitochondrial and vacuolar transporters add further layers linking acidic amino acid flux to cellular metabolism.
Intestinal and epithelial transport defects
The intestinal brush-border membrane is a site of acidic amino acid absorption, and impaired transport there could affect nutrient handling. This makes epithelial transport an important area for studying malabsorption and related conditions.
Membrane environment and transport-related pathology
Sialic acid influences synaptosomal transport of amino acid transmitters, suggesting that changes in membrane glycosylation could contribute to transport-related pathology. This connects GO:0015800 to broader questions of membrane biology in disease.
From acidic amino acid transport-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is a transporter required for acidic amino acid uptake? | CRISPR knockout cell line |
| Does a specific residue control substrate specificity? | Point-mutation knock-in |
| How does a disease-associated variant affect transport? | Knock-in of the variant |
| Where does the transporter localize in the cell? | Tagged knock-in |
| Does increased transporter expression change acidic amino acid flux? | Overexpression model |
| Which genes modify acidic amino acid transport? | CRISPR library screening |
How to Study the acidic amino acid transport Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Membrane vesicle uptake assay | Transport of acidic amino acids across membranes | Intestinal brush-border transport studies |
| Xenopus oocyte expression | Transport activity and modulation | Testing amino-acid-dependent regulation |
| Vesicular transport assay | Loading of acidic amino acids into vesicles | Characterizing sialin function |
| Yeast genetics | Transporter requirement and vacuolar transport | Knockout and tagged knock-in studies |
| Synaptosomal transport assay | Transmitter amino acid transport and sialic acid effects | Membrane environment studies |
| Electrophysiology | Coupled transport and anion conduction | Mechanistic analysis of EAATs |
| CRISPR knockout screening | Genes required for acidic amino acid transport | Functional genomics of transporters |
| Overexpression profiling | Effect of increased transporter levels | Metabolic flux studies |
Transport assays in membrane vesicles and oocytes
Direct measurement of acidic amino acid transport can be performed using membrane vesicle preparations, such as human jejunal brush-border membrane vesicles, or in expression systems like Xenopus laevis oocytes. These assays quantify uptake and allow modulation by substrate availability to be tested.
Functional characterization of vesicular transport
Vesicular acidic amino acid transport can be studied by functionally characterizing proteins such as human sialin, which mediates vesicular excitatory amino acid transport. Such assays reveal how acidic amino acids are loaded into organelles.
Genetic and biochemical analysis in model organisms
Yeast models enable genetic dissection of acidic amino acid transport, including nitrogen-starvation responses and vacuolar transporter families. These systems allow knockout and tagged knock-in approaches to define transporter function.
Membrane and synaptic transport studies
Synaptosomal preparations can be used to study transport of amino acid transmitters and the role of sialic acid in this process. Coupled transport and anion conduction can be analyzed electrophysiologically and biochemically.
How CRISPR Can Be Used to Study GO:0015800 acidic amino acid transport
Knockout
CRISPR knockout of acidic amino acid transporter genes such as SLC1A2 or SLC17A5 can test whether a specific transporter is required for transport. Knockout models are useful for linking genes to GO:0015800 phenotypes.
Point Mutation
Point mutations can be introduced into transporter genes to dissect residues controlling substrate specificity, ion coupling, or anion conduction. Such models help define the molecular basis of coupled transport.
Knock-in
Knock-in of disease-associated variants or tagged transporters allows study of localization and function in a native context. This is particularly useful for vesicular transporters like sialin.
Overexpression
Overexpression of acidic amino acid transporters can reveal how increased transport capacity affects cellular metabolism and signaling. It complements loss-of-function approaches.
How EDITGENE Supports acidic amino acid transport Research
Researchers studying acidic amino acid transport-related genes often need to determine whether a candidate gene is causally involved in transport, how specific residues affect substrate handling, and where the transporter acts within the cell. EDITGENE provides CRISPR-based cell models and screening services designed to answer these questions with publication-ready rigor.
Contact EDITGENE today to design your custom CRISPR model for acidic amino acid transport research.
Frequently Asked Questions About acidic amino acid transport
What is acidic amino acid transport (GO:0015800)?
It is the directed movement of acidic amino acids, which have a pH below 7, into, out of, or within a cell, or between cells, by means of a transporter or pore.
What genes are involved in acidic amino acid transport?
Genes include SLC1A family excitatory amino acid transporters, SLC17A5 (sialin), and yeast vacuolar transporters such as AVT1, AVT3, and AVT4.
Which transporters mediate vesicular acidic amino acid transport?
Human sialin has been functionally characterized as a vesicular excitatory amino acid transporter.
How is acidic amino acid transport regulated?
It can be modulated by amino acid availability and by the membrane environment, including sialic acid.
Why is acidic amino acid transport important for neurons?
It controls glutamate and aspartate levels, which are central to excitatory neurotransmission.
Can acidic amino acid transport be studied in yeast?
Yes, yeast models have been used to study amino acid transport under nitrogen starvation and vacuolar transport families.
What methods measure acidic amino acid transport?
Membrane vesicle uptake assays, Xenopus oocyte expression, vesicular transport assays, and synaptosomal transport assays are commonly used.
How can CRISPR help study acidic amino acid transport?
CRISPR knockout, point mutation, knock-in, and overexpression models can test the causal role of transporter genes.
Is acidic amino acid transport linked to disease?
Yes, transporter dysfunction is linked to neurological and metabolic disease processes.
What is the GO ID for acidic amino acid transport?
The GO ID is GO:0015800.
Conclusion
GO:0015800 (acidic amino acid transport) defines a fundamental biological process that moves acidic amino acids across cellular membranes through transporters and pores. It is central to neurotransmission, metabolism, and epithelial nutrient handling, and it is mediated by a diverse set of proteins including EAATs and sialin. Studying this process with CRISPR-based models and functional transport assays provides a rigorous path to understanding its roles in health and disease.
References
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- 2. Taylor PM et al.. 1996. Amino-acid-dependent modulation of amino acid transport in Xenopus laevis oocytes.. J Exp Biol 199(Pt 4):923-31 PMID: 8788089
- 3. Miyaji T et al.. 2011. Functional characterization of vesicular excitatory amino acid transport by human sialin.. J Neurochem 119(1):1-5 PMID: 21781115
- 4. Woodward JR et al.. 1977. Amino acid transport and metabolism in nitrogen-starved cells of Saccharomyces cerevisiae.. J Bacteriol 130(2):714-23 PMID: 400789
- 5. Avila-Chávez E et al.. 1997. [New concepts in anionic and cationic amino acid transport].. Rev Invest Clin 49(5):411-24 PMID: 9527701
- 6. Russnak R et al.. 2001. A family of yeast proteins mediating bidirectional vacuolar amino acid transport.. J Biol Chem 276(26):23849-57 PMID: 11274162
- 7. Rajendran VM et al.. 1987. Transport of acidic amino acids by human jejunal brush-border membrane vesicles.. Am J Physiol 252(1 Pt 1):G33-9 PMID: 2880511
- 8. Zaleska MM et al.. 1987. Role of sialic acid in synaptosomal transport of amino acid transmitters.. Proc Natl Acad Sci U S A 84(6):1709-12 PMID: 3470752
