GO:0015174 basic amino acid transmembrane transporter activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0015174 describes the molecular function of moving basic amino acids (arginine, lysine, histidine, ornithine) across biological membranes.
• These transporters are secondary active carriers that couple substrate flux to Na+ or H+ gradients, or facilitative uniporters that respond to substrate availability.
• SLC7A1 (CAT-1) is a canonical system y+ transporter for cationic amino acids and is induced by oncogenic KRAS, creating a therapeutic vulnerability in non-small cell lung cancer.
• SLC38A9 acts as a lysosomal arginine sensor that signals amino acid sufficiency to mTORC1, linking transport activity to growth control.
• SLC38A5 (SNAT5) is a glutamine and amino acid transporter with pro-cancer roles in the tumor microenvironment.
• CRISPR knockout, point-mutation, knock-in, and overexpression models are essential to dissect transporter specificity, regulation, and disease relevance [2,5].
Description
Basic amino acid transmembrane transporter activity (GO:0015174) is a molecular function that enables the transfer of basic amino acids from one side of a membrane to the other. Basic amino acids, including arginine, lysine, histidine, and ornithine, carry a positive charge at physiological pH, and their movement across membranes is mediated by specialized transport proteins. This activity is fundamental to nitrogen metabolism, protein synthesis, cell signaling, and immune function, and its dysregulation is increasingly linked to cancer and metabolic disorders [1,2]. Researchers study these transporters to understand how cells acquire essential amino acids, how nutrient sensing is coupled to growth, and how to target transporter dependencies therapeutically [2,5].
basic amino acid transmembrane transporter activity At A Glance
| GO ID | GO:0015174 |
|---|---|
| GO term | basic amino acid transmembrane transporter activity |
| Ontology | molecular_function |
| Synonym | basic amino acid permease activity; basic amino acid transporter activity; cationic amino acid transmembrane transporter activity |
| Major function | Transfer of basic amino acids (e.g., arginine, lysine, histidine, ornithine) across membranes |
| Substrate specificity | Positively charged amino acids at pH 7.3 |
| Transport mechanism | Secondary active transport or facilitative diffusion, often coupled to Na+ or H+ gradients |
| Representative genes | SLC7A1, SLC7A2, SLC7A3, SLC3A2, SLC38A9, SLC38A5, SLC25A29, SLC25A15 |
| Disease relevance | Cancer, metabolic disorders, immune dysfunction, lysosomal storage diseases |
What Is GO:0015174?
GO:0015174, basic amino acid transmembrane transporter activity, is defined as the function that enables the transfer of basic amino acids from one side of a membrane to the other, where basic amino acids have side chains with a positive charge at pH 7.3. This activity is also known as basic amino acid permease activity, basic amino acid transporter activity, or cationic amino acid transmembrane transporter activity. It is a molecular function term in the Gene Ontology and is distinct from transport of neutral or acidic amino acids.
Why Is basic amino acid transmembrane transporter activity Important in Cell Biology?
Basic amino acid transmembrane transporter activity is critical for cellular nitrogen balance, protein synthesis, and signal transduction. Arginine and lysine are essential for cell proliferation and immune responses, and their uptake is often rate-limiting in tumors. Transporters such as SLC7A1 and SLC38A9 directly influence mTORC1 signaling, linking amino acid availability to growth control [2,5]. Consequently, these transporters are emerging as therapeutic targets and biomarkers in oncology and metabolic disease [1,2].
• Supplies cationic amino acids for protein synthesis and cell growth.
• Regulates mTORC1 signaling through lysosomal arginine sensing.
• Supports tumor proliferation and survival in KRAS-driven cancers.
• Modulates immune cell function by controlling arginine availability.
• Maintains nitrogen homeostasis and urea cycle intermediates.
• Contributes to drug resistance and metabolic reprogramming in cancer.
• Provides targets for transporter-focused drug discovery.
• Enables genetic screens to identify synthetic lethal interactions.
• Links membrane transport to autophagy and lysosomal function.
• Offers biomarkers for patient stratification in NSCLC and other cancers.
What Happens During basic amino acid transmembrane transporter activity?
Substrate recognition and binding
In simple terms: The transporter first grabs the basic amino acid from one side of the membrane.
Basic amino acid transporters recognize their substrates through a binding pocket that accommodates the positively charged side chain. Structural and functional studies of secondary transporters have revealed that charged residues within transmembrane helices coordinate the amino acid headgroup and the cationic side chain, ensuring specificity for arginine, lysine, or histidine. In the sulfate transporter SHST1, interactions between charged residues within transmembrane helices are critical for substrate binding and transport, illustrating a conserved principle for charged solute recognition.
Conformational cycling and translocation
In simple terms: The transporter changes shape to move the amino acid across the membrane.
After binding, the transporter undergoes a series of conformational changes that expose the substrate to the opposite side of the membrane. This alternating-access mechanism is common to secondary transporters and is driven by the energy stored in ion gradients or by substrate concentration gradients. Computational modeling approaches have been developed to simulate these conformational transitions and to predict ligand interactions for transmembrane transporters.
Coupling to ion gradients
In simple terms: The transporter uses the flow of ions like sodium or protons to power amino acid uptake.
Many basic amino acid transporters are secondary active transporters that couple substrate movement to the inward flow of Na+ or H+. The stoichiometry and ion dependence vary among families, but the coupling allows cells to accumulate basic amino acids against their concentration gradient. For example, SLC38A9 is a lysosomal transporter that uses arginine availability to signal through mTORC1, integrating transport with nutrient sensing.
Regulation by cellular demand
In simple terms: The cell adjusts how many transporters it makes based on its need for amino acids.
Transport activity is regulated at multiple levels, including transcription, membrane trafficking, and post-translational modifications. Oncogenic KRAS induces arginine auxotrophy and upregulates SLC7A1 to meet increased demand for cationic amino acids in non-small cell lung cancer. Similarly, SLC38A5 expression is elevated in the tumor microenvironment and supports pro-cancer metabolic programs.
Key Genes Involved in GO:0015174 basic amino acid transmembrane transporter activity
The following genes encode transporters or associated subunits that mediate basic amino acid transmembrane transporter activity.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SLC7A1 | High-affinity cationic amino acid transporter (system y+) | KRAS-driven NSCLC vulnerability; arginine uptake |
| SLC7A2 | Cationic amino acid transporter (system y+) | Immune regulation and nitrogen metabolism |
| SLC7A3 | Cationic amino acid transporter (system y+) | Neuronal and testicular amino acid supply |
| SLC3A2 | Heavy subunit of heterodimeric amino acid transporters | Chaperone-like function for SLC7A1 and others |
| SLC38A9 | Lysosomal arginine sensor and transporter | mTORC1 signaling and autophagy |
| SLC38A5 | Glutamine and amino acid transporter (SNAT5) | Tumor microenvironment and cancer metabolism |
| SLC25A29 | Mitochondrial basic amino acid transporter | Urea cycle and mitochondrial transport |
| SLC25A15 | Mitochondrial ornithine transporter | Hyperornithinemia-hyperammonemia-homocitrullinuria syndrome |
| SLC7A5 | L-type amino acid transporter 1 (LAT1) | Leucine and large neutral amino acid transport |
| SLC7A11 | Cystine/glutamate antiporter | Redox balance and ferroptosis |
| SLC1A5 | Glutamine transporter | Liver regeneration and cancer metabolism |
| SLC6A14 | Na+- and Cl--dependent amino acid transporter | Arginine uptake in cancer |
| SLC6A19 | Neutral amino acid transporter | Hartnup disorder |
| SLC36A1 | Proton-coupled amino acid transporter | Lysosomal amino acid efflux |
| SLC43A1 | L-type amino acid transporter | Branched-chain amino acid transport |
| SLC43A2 | L-type amino acid transporter | Branched-chain amino acid transport |
| SLC16A10 | Aromatic amino acid transporter | Thyroid hormone and amino acid transport |
How Is basic amino acid transmembrane transporter activity Regulated?
Basic amino acid transmembrane transporter activity is regulated by nutrient-sensing pathways, oncogenic signaling, and membrane trafficking. The lysosomal transporter SLC38A9 senses arginine sufficiency and signals to mTORC1, thereby coupling transport activity to cell growth and autophagy. Oncogenic KRAS induces arginine auxotrophy and upregulates SLC7A1, making transporter inhibition a therapeutic strategy in non-small cell lung cancer. SLC38A5 expression is induced in the tumor microenvironment and supports pro-cancer metabolic reprogramming. Additionally, the retrieval receptor Rer1p dynamically localizes to the Golgi apparatus and regulates endoplasmic reticulum membrane protein retrieval, which may influence transporter trafficking.
basic amino acid transmembrane transporter activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC7A1 | Non-small cell lung cancer (KRAS-driven) | SLC7A1 knockout and point-mutation models in NSCLC cell lines |
| SLC38A9 | Lysosomal nutrient sensing and mTORC1 dysregulation | SLC38A9 knockout and knock-in models for arginine sensing |
| SLC38A5 | Tumor microenvironment and cancer metabolism | SLC38A5 overexpression and knockout in cancer cells |
| SLC25A15 | Hyperornithinemia-hyperammonemia-homocitrullinuria syndrome | SLC25A15 point-mutation knock-in models |
| SLC3A2 | Heterodimeric amino acid transporter dysfunction | SLC3A2 knockout and tagged knock-in for trafficking studies |
Cancer metabolism and transporter dependencies
Basic amino acid transporters are frequently upregulated in cancer to support increased demand for arginine, lysine, and other cationic amino acids. Oncogenic KRAS induces arginine auxotrophy and confers a therapeutic vulnerability to SLC7A1 inhibition in non-small cell lung cancer. SLC38A5 (SNAT5) is overexpressed in the tumor microenvironment and promotes pro-cancer roles, making it a potential target for metabolic therapy. These findings highlight the importance of transporter-mediated amino acid uptake in tumor growth and survival.
Lysosomal function and mTORC1 signaling
SLC38A9 is a lysosomal amino acid transporter that signals arginine sufficiency to mTORC1. Dysregulation of this pathway can lead to altered autophagy and metabolic disorders. Mutations or expression changes in SLC38A9 may affect lysosomal amino acid efflux and mTORC1 activity, contributing to diseases characterized by defective nutrient sensing.
Metabolic and immune disorders
Arginine and lysine transport are critical for immune cell function and nitrogen homeostasis. Defects in cationic amino acid transport can impair T cell proliferation and macrophage function, linking GO:0015174 to immune dysfunction and inflammatory diseases. Additionally, mitochondrial transporters such as SLC25A15 are associated with hyperornithinemia-hyperammonemia-homocitrullinuria syndrome, a urea cycle disorder.
From basic amino acid transmembrane transporter activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of SLC7A1 impair arginine uptake and tumor growth? | SLC7A1 knockout in NSCLC cell lines |
| How does SLC38A9 sense arginine to activate mTORC1? | SLC38A9 point-mutation and knock-in models |
| What is the role of SLC38A5 in the tumor microenvironment? | SLC38A5 overexpression and knockout in cancer cells |
| How does SLC3A2 trafficking affect transporter surface expression? | SLC3A2 tagged knock-in for imaging |
| Can SLC25A15 mutations cause urea cycle dysfunction? | SLC25A15 point-mutation knock-in in hepatocytes |
| Which transporters are essential for immune cell activation? | CRISPR library screening in primary immune cells |
How to Study the basic amino acid transmembrane transporter activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Radiolabeled uptake assay | Transport rate and kinetics | Determining Km and ion dependence |
| CRISPR knockout screening | Gene essentiality and transporter dependencies | Identifying SLC7A1 as a cancer vulnerability |
| Proteomics (LC-MS/MS) | Protein expression and interactions | Characterizing heterodimeric transporters |
| Live-cell imaging | Subcellular localization and trafficking | Studying Rer1p and transporter dynamics |
| RNA-seq | Transcriptional regulation of transporters | Measuring SLC38A5 induction in tumors |
| mTORC1 reporter assays | Nutrient signaling activity | Assessing SLC38A9 function |
| Structural modeling | Ligand binding and conformational states | Predicting transporter-drug interactions |
| Site-directed mutagenesis | Residue-level function | Mapping charged residues in SHST1 |
Transport assays and radiolabeled uptake
Direct measurement of basic amino acid transport is performed using radiolabeled substrates such as [3H]-arginine or [14C]-lysine. Cells expressing wild-type or mutant transporters are incubated with labeled substrate, and uptake is quantified by scintillation counting. This method is used to determine Km, Vmax, and ion dependence of transporters like SLC7A1.
Genetic screens and CRISPR knockout
CRISPR knockout screens can identify genes required for basic amino acid uptake and cell survival under amino acid restriction. For example, SLC7A1 was identified as a vulnerability in KRAS-driven NSCLC using functional genomics. Pooled CRISPR libraries targeting solute carriers enable systematic discovery of transporter dependencies.
Proteomics and interactomics
Mass spectrometry-based proteomics can quantify transporter expression and identify interacting partners. Affinity purification of tagged transporters followed by LC-MS/MS reveals subunits and regulatory proteins. This approach is useful for studying heterodimeric transporters such as SLC3A2-SLC7A1.
Imaging and subcellular localization
Fluorescence microscopy of GFP- or epitope-tagged transporters reveals subcellular localization and trafficking. For example, Rer1p dynamically localizes to the Golgi apparatus and regulates ER membrane protein retrieval, which can be studied using live-cell imaging. Lysosomal transporters like SLC38A9 can be visualized with lysosomal markers.
How CRISPR Can Be Used to Study GO:0015174 basic amino acid transmembrane transporter activity
Knockout
CRISPR knockout of basic amino acid transporter genes such as SLC7A1 or SLC38A9 is used to abolish transport activity and assess downstream effects on cell growth, mTORC1 signaling, and metabolism [2,5]. Knockout models are essential for validating transporter dependencies identified in screens.
Point Mutation
Point mutations in transporter genes can mimic disease-associated variants or disrupt key residues in the substrate binding pocket. For example, mutations in SLC25A15 cause hyperornithinemia-hyperammonemia-homocitrullinuria syndrome, and point-mutation models help dissect the molecular basis of transport defects.
Knock-in
Knock-in of tagged or mutant transporters allows precise tracking of localization and function. Tagged knock-in of SLC3A2 or SLC7A1 enables imaging of surface expression and trafficking in live cells. Knock-in of disease variants can recapitulate human phenotypes in model systems.
Overexpression
Overexpression of transporters such as SLC38A5 or SLC7A1 is used to study gain-of-function effects, including enhanced amino acid uptake, proliferation, and tumor growth [1,2]. Overexpression models are valuable for testing transporter inhibitors and metabolic dependencies.
How EDITGENE Supports basic amino acid transmembrane transporter activity Research
Researchers studying basic amino acid transmembrane transporter activity-related genes often need to determine whether a candidate gene is causally involved in amino acid uptake, signaling, or disease. EDITGENE provides comprehensive CRISPR-based services to generate knockout, point-mutation, knock-in, and overexpression cell models, as well as library screening and bioinformatics support, enabling rigorous functional validation of transporters like SLC7A1, SLC38A9, and SLC38A5.
Contact EDITGENE today to design your custom CRISPR model for basic amino acid transmembrane transporter activity research.
Frequently Asked Questions About basic amino acid transmembrane transporter activity
What is basic amino acid transmembrane transporter activity?
It is a molecular function (GO:0015174) that enables the transfer of basic amino acids such as arginine, lysine, and histidine across membranes.
What genes are involved in basic amino acid transmembrane transporter activity?
Key genes include SLC7A1, SLC7A2, SLC7A3, SLC3A2, SLC38A9, SLC38A5, SLC25A29, and SLC25A15 [1,2,5].
How is basic amino acid transport regulated?
It is regulated by nutrient-sensing pathways such as mTORC1, oncogenic signaling like KRAS, and membrane trafficking [2,5].
What diseases are linked to basic amino acid transporters?
They are linked to cancer, lysosomal storage disorders, immune dysfunction, and urea cycle disorders [1,2,5].
What is the role of SLC7A1 in cancer?
SLC7A1 mediates arginine uptake and is a therapeutic vulnerability in KRAS-driven non-small cell lung cancer.
How does SLC38A9 signal to mTORC1?
SLC38A9 senses lysosomal arginine levels and signals amino acid sufficiency to mTORC1.
What is SLC38A5 and why is it important?
SLC38A5 (SNAT5) is a glutamine and amino acid transporter with pro-cancer roles in the tumor microenvironment.
What methods are used to study basic amino acid transporters?
Radiolabeled uptake assays, CRISPR screens, proteomics, imaging, and structural modeling are commonly used [2,3,6,7].
Can CRISPR be used to study basic amino acid transporters?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to dissect transporter function [2,5].
What is the clinical relevance of basic amino acid transport?
It informs cancer therapy, metabolic disease, and immune modulation strategies [1,2].
Conclusion
Basic amino acid transmembrane transporter activity (GO:0015174) is a fundamental molecular function that controls the uptake of cationic amino acids and integrates with nutrient signaling, metabolism, and disease. Key transporters such as SLC7A1, SLC38A9, and SLC38A5 are emerging as critical players in cancer and metabolic disorders [1,2,5]. Understanding their mechanism and regulation requires robust experimental models, and CRISPR-based approaches provide powerful tools for functional validation. EDITGENE offers comprehensive services to accelerate research on these transporters.
References
- 1. Taurino G et al.. 2023. The SLC38A5/SNAT5 amino acid transporter: from pathophysiology to pro-cancer roles in the tumor microenvironment.. Am J Physiol Cell Physiol 325(2):C550-C562 PMID: 37458433
- 2. Gai X et al.. 2024. Oncogenic KRAS Induces Arginine Auxotrophy and Confers a Therapeutic Vulnerability to SLC7A1 Inhibition in Non-Small Cell Lung Cancer.. Cancer Res 84(12):1963-1977 PMID: 38502865
- 3. Sato K et al.. 2001. Rer1p, a retrieval receptor for endoplasmic reticulum membrane proteins, is dynamically localized to the Golgi apparatus by coatomer.. J Cell Biol 152(5):935-44 PMID: 11238450
- 4. Duan Y et al.. 2025. SLC1A5-dependent glutamine uptake in hepatocytes promotes liver regeneration.. Hepatol Commun 9(8) PMID: 40658789
- 5. Wang S et al.. 2015. Metabolism. Lysosomal amino acid transporter SLC38A9 signals arginine sufficiency to mTORC1.. Science 347(6218):188-94 PMID: 25567906
- 6. Grandits M et al.. 2024. Ligand- and Structure-based Approaches for Transmembrane Transporter Modeling.. Curr Drug Res Rev 16(2):81-93 PMID: 37157206
- 7. Schweikhard ES et al.. 2012. Amino acid secondary transporters: toward a common transport mechanism.. Curr Top Membr 70:1-28 PMID: 23177982
- 8. Shelden MC et al.. 2003. Interactions between charged amino acid residues within transmembrane helices in the sulfate transporter SHST1.. Biochemistry 42(44):12941-9 PMID: 14596609
