GO:0015819 lysine transport: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0015819 (lysine transport) describes the directed movement of the amino acid lysine across cellular membranes via transporters or pores.
• Lysine transport is mediated by multiple systems including system y+L, which is defective in lysinuric protein intolerance.
• The human intestinal cell line Caco-2 exhibits Na+-independent lysine transport, highlighting the diversity of transport mechanisms.
• Bacterial lysine permeases such as LysP from Pseudomonas aeruginosa show high specificity for lysine, with structural studies revealing key binding residues.
• Dietary lysine levels can modulate lysine transport activity in the brush-border membrane of the chicken jejunum.
• Lysine transport is critical for protein synthesis, cell growth, and metabolic regulation, and its dysfunction is linked to inherited disorders and cancer.
Description
Lysine transport (GO:0015819) is the biological process by which the essential amino acid lysine is moved into, out of, or within a cell, or between cells, through the action of transporters or pores. As an essential amino acid, lysine cannot be synthesized by humans and must be obtained from the diet, making its transport across cellular membranes a fundamental requirement for protein synthesis, cell growth, and metabolic homeostasis. The process is mediated by a variety of transport systems that differ in ion dependence, substrate specificity, and tissue distribution. Defects in lysine transport are associated with human diseases such as lysinuric protein intolerance, a rare inherited disorder caused by mutations in the y+L amino acid transporter. In bacteria, lysine permeases are essential for nutrient uptake and have been characterized structurally, providing insights into substrate recognition and transport mechanisms. Understanding lysine transport is therefore crucial for researchers studying amino acid metabolism, membrane biology, and disease mechanisms.
lysine transport At A Glance
| GO ID | GO:0015819 |
|---|---|
| GO term | lysine transport |
| Ontology | biological_process |
| Synonym | L-lysine import, L-lysine transport, lysine import, lysine uptake |
| Major function | Directed movement of lysine across cellular membranes |
| Cellular location | Plasma membrane, organelle membranes, and transport vesicles |
| Representative transporters | System y+L (SLC7A6/SLC7A7), LysP permease, and other amino acid transporters |
| Associated diseases | Lysinuric protein intolerance, cancer metabolism |
| Research methods | Transport assays, structural biology, CRISPR screens, metabolomics |
What Is GO:0015819?
GO:0015819, lysine transport, is defined as the directed movement of lysine (2,6-diaminohexanoic acid) into, out of, or within a cell, or between cells, by means of some agent such as a transporter or pore. This process encompasses the import, export, and intracellular distribution of lysine, and is mediated by specific membrane proteins that recognize and translocate lysine across lipid bilayers.
Why Is lysine transport Important in Cell Biology?
Lysine transport is essential for maintaining intracellular lysine levels required for protein synthesis, post-translational modifications, and metabolic signaling. Dysregulation of lysine transport contributes to inherited metabolic disorders such as lysinuric protein intolerance and is implicated in cancer progression, where altered amino acid uptake supports rapid cell growth. Moreover, lysine transport systems are potential drug targets in pathogens and cancer cells, and understanding their mechanisms can inform therapeutic strategies.
• Provides essential lysine for protein synthesis and cell proliferation.
• Defects in lysine transport cause lysinuric protein intolerance, a rare inherited disease.
• Lysine transport is linked to cancer metabolism and tumor progression.
• Bacterial lysine permeases are targets for antimicrobial development.
• Dietary lysine modulates transport activity in intestinal brush-border membranes.
• Lysine transport influences pH-dependent transport mechanisms via residues like Lys38 in MCT1.
• Lysine availability affects mitochondrial function through SIRT5-mediated desuccinylation.
• Transport systems like y+L are critical for cationic amino acid homeostasis in erythrocytes.
• Lysine transport is a model for studying membrane protein structure and function.
• Altered lysine transport can affect epigenetic modifications such as histone lactylation.
What Happens During lysine transport?
Substrate recognition and binding
In simple terms: The transporter first grabs the lysine molecule.
Lysine transporters specifically recognize the amino acid through binding pockets that accommodate its positively charged side chain. Structural studies of the Pseudomonas aeruginosa lysine permease LysP reveal a high specificity for lysine, with key residues forming a binding site that discriminates against other amino acids. In human cells, system y+L transports lysine in a Na+-independent manner, often in exchange for other amino acids.
Translocation across the membrane
In simple terms: The transporter then moves lysine across the cell membrane.
Upon binding, the transporter undergoes conformational changes that allow lysine to pass through the lipid bilayer. In Caco-2 intestinal cells, lysine transport is Na+-independent, suggesting a facilitated diffusion or exchange mechanism. The human monocarboxylate transporter 1 (MCT1) requires a specific lysine residue (Lys38) for pH-dependent transport, illustrating how charged residues can influence translocation.
Release and intracellular distribution
In simple terms: Once inside, lysine is released for cellular use.
After translocation, lysine is released into the cytoplasm or organelles. It can be used for protein synthesis or further transported into mitochondria and other compartments. Mitochondrial pyruvate carrier studies highlight the importance of specific transport mechanisms for metabolites, and similar principles apply to lysine distribution. Lysine can also be desuccinylated by SIRT5, linking transport to mitochondrial metabolism.
Regulation by dietary and hormonal factors
In simple terms: The amount of lysine transport can change based on diet and signals.
Lysine transport activity is regulated by dietary lysine levels. In chickens fed a lysine-enriched diet, L-lysine transport by the brush-border membrane of the jejunum is altered, demonstrating adaptive regulation. Hormonal and metabolic signals may also modulate transporter expression, though specific pathways require further study.
Key Genes Involved in GO:0015819 lysine transport
The following genes and proteins are key players in lysine transport, as supported by experimental evidence.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SLC7A7 | Light subunit of system y+L transporter; mediates lysine transport | Mutations cause lysinuric protein intolerance |
| SLC7A6 | Light subunit of system y+L; transports cationic amino acids | Potential role in amino acid homeostasis |
| SLC3A2 | Heavy subunit of system y+L; chaperone for SLC7A7 | Required for functional y+L activity |
| LysP | Bacterial lysine permease from Pseudomonas aeruginosa | Structural model for specific lysine transport |
| MCT1 (SLC16A1) | Monocarboxylate transporter; Lys38 affects pH-dependent transport | Lysine residue critical for function |
| SIRT5 | Lysine desuccinylase; binds cardiolipin and regulates electron transport chain | Links lysine metabolism to mitochondrial function |
| SLC7A1 | Cationic amino acid transporter (CAT-1); transports lysine | Broad amino acid transport |
| SLC7A2 | CAT-2; transports lysine and arginine | Inducible in various tissues |
| SLC7A3 | CAT-3; transports cationic amino acids | Neuronal and testicular expression |
| SLC7A5 | L-type amino acid transporter 1 (LAT1); transports large neutral amino acids | Indirectly affects lysine uptake |
| SLC7A8 | LAT2; transports neutral amino acids | May influence lysine availability |
| SLC25A15 | Mitochondrial ornithine transporter; related to lysine metabolism | Involved in hyperornithinemia-hyperammonemia-homocitrullinuria syndrome |
| SLC25A29 | Mitochondrial lysine transporter | Potential role in lysine catabolism |
| SLC66A1 | Lysosomal amino acid transporter; may transport lysine | Lysosomal storage disorders |
| SLC38A9 | Lysosomal arginine sensor; may influence lysine transport | mTORC1 signaling |
| SLC36A1 | Proton-coupled amino acid transporter; transports lysine | Intestinal absorption |
| SLC6A14 | Na+/Cl- dependent amino acid transporter; transports lysine | Potential drug target in cancer |
| SLC1A5 | Neutral amino acid transporter; indirect role in lysine uptake | Cancer metabolism |
How Is lysine transport Regulated?
Lysine transport is regulated at multiple levels. Dietary lysine availability modulates transport activity in intestinal brush-border membranes, as shown in chickens fed a lysine-enriched diet. Hormonal signals and cellular stress can alter transporter expression. For example, the mTORC1 pathway senses lysine levels through SLC38A9 and other sensors, though direct evidence for lysine-specific regulation is limited. Additionally, post-translational modifications such as desuccinylation by SIRT5 can affect mitochondrial enzymes involved in lysine metabolism. In cancer, oncogenic KRAS mutations increase histone H3 lysine 9 lactylation, which promotes cholesterol transporter expression, indicating crosstalk between lysine metabolism and gene regulation.
lysine transport and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC7A7 | Lysinuric protein intolerance | Knockout mice or patient-derived iPSCs |
| KRAS | Colorectal cancer progression via H3K9 lactylation | KRAS mutant knock-in cell lines |
| SIRT5 | Mitochondrial dysfunction and metabolic regulation | SIRT5 knockout cells |
| MCT1 (SLC16A1) | pH-dependent transport defects | Point mutation at Lys38 |
| LysP | Bacterial lysine uptake | Bacterial knockout strains |
Lysinuric protein intolerance
Lysinuric protein intolerance (LPI) is a rare autosomal recessive disorder caused by mutations in SLC7A7, which encodes the light subunit of the y+L amino acid transporter. Defective lysine transport in erythrocytes and other tissues leads to low plasma lysine and arginine levels, causing failure to thrive, vomiting, and hyperammonemia after protein-rich meals. Diagnosis often involves measuring cationic amino acid transport in erythrocytes, and treatment includes citrulline supplementation and protein-restricted diet.
Cancer metabolism
Altered lysine transport supports the metabolic demands of cancer cells. KRAS-mutant colorectal cancer cells exhibit increased histone H3 lysine 9 lactylation, which upregulates cholesterol transporter GRAMD1A and promotes tumor progression. This highlights how lysine availability and transport can influence epigenetic modifications and oncogenic signaling. Targeting lysine transporters such as SLC6A14 may offer therapeutic opportunities in cancers dependent on lysine uptake.
Mitochondrial dysfunction
Lysine transport into mitochondria is essential for oxidative metabolism. SIRT5, a mitochondrial desuccinylase, binds cardiolipin and regulates the electron transport chain, linking lysine metabolism to mitochondrial function. Disruption of mitochondrial lysine transport could contribute to metabolic disorders, though specific transporters remain under investigation.
From lysine transport-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does SLC7A7 loss impair lysine transport? | SLC7A7 knockout cell line (e.g., HEK293 or Caco-2) |
| How does Lys38 mutation affect MCT1 function? | Point mutation knock-in at Lys38 in MCT1 |
| Can overexpression of LysP increase lysine uptake? | LysP overexpression in E. coli or P. aeruginosa |
| What is the role of SIRT5 in mitochondrial lysine metabolism? | SIRT5 knockout and tagged knock-in for localization |
| Does dietary lysine regulate transporter expression? | In vivo chicken model with lysine-enriched diet |
| Can CRISPR screen identify novel lysine transporters? | Genome-wide CRISPR knockout library in cancer cells |
How to Study the lysine transport Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Radiolabeled uptake assay | Transport rate and kinetics | Characterizing lysine transport in cell lines |
| Cryo-EM/X-ray crystallography | Three-dimensional structure | Understanding substrate binding |
| CRISPR knockout screen | Gene essentiality for transport | Identifying novel lysine transporters |
| Metabolomics | Intracellular lysine levels | Assessing transport impact on metabolism |
| Western blot | Transporter protein expression | Validating knockout or overexpression |
| qPCR | Transporter mRNA levels | Gene expression analysis |
| Patch-clamp | Electrogenic transport currents | Real-time transport activity |
| Proteomics | Global protein changes | Systems-level analysis |
Transport assays
Radiolabeled or fluorescent lysine uptake assays are used to measure transport activity in cells or membrane vesicles. For example, Na+-independent lysine transport in Caco-2 cells was characterized using such assays. These methods can determine kinetic parameters and substrate specificity.
Structural biology
X-ray crystallography and cryo-EM reveal the atomic structure of lysine transporters. The structure of Pseudomonas aeruginosa LysP provided insights into lysine binding and specificity. Such studies guide mutagenesis and drug design.
CRISPR screening
Genome-wide CRISPR knockout screens can identify genes essential for lysine transport. This approach is powerful for discovering novel transporters and regulatory factors, especially in cancer cells where lysine uptake is critical.
Metabolomics and proteomics
Mass spectrometry-based metabolomics quantifies intracellular lysine and related metabolites, while proteomics assesses transporter expression. These methods complement functional assays to provide a systems-level view of lysine transport.
How CRISPR Can Be Used to Study GO:0015819 lysine transport
Knockout
CRISPR knockout of lysine transporter genes such as SLC7A7 or SLC7A6 can abolish transport activity, providing causal evidence for their role. For example, SLC7A7 knockout cells model lysinuric protein intolerance and can be used to test therapeutic interventions. Genome-wide knockout screens can identify novel genes required for lysine uptake in cancer cells.
Point Mutation
Point mutations can mimic disease-associated variants or probe functional residues. For instance, mutating Lys38 in MCT1 to alanine can test its role in pH-dependent transport. Similarly, mutations in the lysine binding pocket of LysP can validate structural findings.
Knock-in
Knock-in of tagged transporters (e.g., GFP-SLC7A7) allows visualization and localization studies. Knock-in of disease mutations, such as those found in LPI patients, creates isogenic models to study pathogenesis. Tagged knock-in can also facilitate interactome analysis.
Overexpression
Overexpression of lysine transporters like LysP or SLC7A7 can increase lysine uptake and alter cellular metabolism. This approach is useful for studying transport kinetics, drug sensitivity, and metabolic reprogramming. Overexpression in cancer cells can model the increased lysine demand of tumors.
How EDITGENE Supports lysine transport Research
Researchers studying lysine transport-related genes often need to determine whether a candidate gene is causally involved in lysine uptake, metabolism, or disease. CRISPR-based models provide precise tools to dissect gene function, from complete knockout to subtle point mutations, enabling rigorous mechanistic studies.
Contact EDITGENE today to design your custom CRISPR model for lysine transport research.
Frequently Asked Questions About lysine transport
What is lysine transport (GO:0015819)?
Lysine transport is the biological process of moving the amino acid lysine across cellular membranes via transporters or pores, as defined by GO:0015819.
What genes are involved in lysine transport?
Key genes include SLC7A7, SLC7A6, SLC3A2 (system y+L), LysP in bacteria, and MCT1 (SLC16A1), among others.
How is lysine transported into cells?
Lysine is transported by specific membrane proteins such as system y+L, which exchanges cationic amino acids, or by Na+-independent transporters in intestinal cells.
What is lysinuric protein intolerance?
It is a rare inherited disorder caused by mutations in SLC7A7, leading to defective lysine transport and low plasma lysine levels.
Is lysine transport Na+-dependent?
Some lysine transporters are Na+-independent, such as those in Caco-2 cells, while others may be Na+-dependent depending on the system.
How does diet affect lysine transport?
Dietary lysine levels can modulate transport activity; a lysine-enriched diet alters L-lysine transport in chicken jejunum brush-border membranes.
What is the role of lysine transport in cancer?
Cancer cells often upregulate lysine transporters to support growth; KRAS mutations increase histone lactylation and cholesterol transporter expression.
What methods are used to study lysine transport?
Common methods include radiolabeled uptake assays, structural biology (cryo-EM), CRISPR screens, and metabolomics.
Can CRISPR be used to study lysine transport?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are powerful tools to dissect gene function in lysine transport.
What diseases are linked to lysine transport defects?
Lysinuric protein intolerance is directly linked; cancer and mitochondrial dysfunction also involve altered lysine transport.
Conclusion
Lysine transport (GO:0015819) is a fundamental biological process required for amino acid homeostasis, protein synthesis, and cellular metabolism. Dysregulation of lysine transporters is implicated in inherited diseases like lysinuric protein intolerance and in cancer progression. Advances in structural biology and CRISPR-based models continue to unravel the molecular mechanisms and regulatory networks governing lysine transport, offering new avenues for therapeutic intervention. Researchers can leverage EDITGENE's services to create precise cellular models and accelerate discoveries in this field.
References
- 1. Bicer D et al.. 2025. Structural basis of specific lysine transport by Pseudomonas aeruginosa permease LysP.. Nat Commun 17(1):37 PMID: 41345107
- 2. Zhang C et al.. 2025. KRAS mutation increases histone H3 lysine 9 lactylation (H3K9la) to promote colorectal cancer progression by facilitating cholesterol transporter GRAMD1A expression.. Cell Death Differ 32(12):2225-2238 PMID: 40707783
- 3. Thwaites DT et al.. 1996. Na+-independent lysine transport in human intestinal Caco-2 cells.. J Membr Biol 151(3):215-24 PMID: 8661509
- 4. Yamaguchi A et al.. 2020. Extracellular lysine 38 plays a crucial role in pH-dependent transport via human monocarboxylate transporter 1.. Biochim Biophys Acta Biomembr 1862(2):183068 PMID: 31593685
- 5. Sichrovsky M et al.. 2025. Molecular basis of pyruvate transport and inhibition of the human mitochondrial pyruvate carrier.. Sci Adv 11(16):eadw1489 PMID: 40249800
- 6. Zhang Y et al.. 2017. Lysine desuccinylase SIRT5 binds to cardiolipin and regulates the electron transport chain.. J Biol Chem 292(24):10239-10249 PMID: 28458255
- 7. Boyd CA et al.. 2000. Cationic amino acid transport through system y+L in erythrocytes of patients with lysinuric protein intolerance.. Pflugers Arch 439(5):513-6 PMID: 10764208
- 8. Torras-Llort M et al.. 1998. Effect of a lysine-enriched diet on L-lysine transport by the brush-border membrane of the chicken jejunum.. Am J Physiol 274(1):R69-75 PMID: 9458900
