GO:0006857 oligopeptide transport: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0006857 oligopeptide transport describes the directed movement of short peptides (2-20 amino acids) across membranes or within cells via transporters or pores.
• Proton-coupled oligopeptide transporters (POTs) of the SLC15 family are the best-characterized mediators of oligopeptide transport in mammals.
• Oligopeptide transport is essential for nutrient uptake, drug absorption, and intercellular signaling in organisms from bacteria to humans.
• In the brain, SLC15 transporters contribute to the clearance and transport of neuroactive peptides, including amyloid-beta, linking the process to neurodegeneration.
• Pathogens such as Candida albicans and Chlamydia trachomatis rely on oligopeptide transporters for nutrient acquisition and cell wall recycling, making them potential drug targets.
• CRISPR-based knockout, knock-in, and overexpression models enable precise dissection of oligopeptide transporter function in health and disease.
Description
Oligopeptide transport (GO:0006857) is a fundamental biological process that mediates the movement of short peptides, typically 2 to 20 amino acid residues, across cellular membranes or between cellular compartments. This process is essential for nutrient acquisition, cellular signaling, and the uptake of peptide-based drugs, and it is conserved from bacteria to humans. The transporters responsible for this activity, such as those in the proton-coupled oligopeptide transporter (POT) family, are critical for maintaining peptide homeostasis in various tissues. In mammals, oligopeptide transport is particularly important in the intestine, kidney, and brain, where it facilitates the absorption of dietary peptides and the clearance of neuroactive peptides. In microorganisms, oligopeptide transporters contribute to nutrient scavenging and can also mediate the uptake of antimicrobial peptides, influencing drug susceptibility. The process is also implicated in bacterial cell wall recycling, as seen in Chlamydia trachomatis, where the oligopeptide transporter performs dual functions. Given its broad physiological and pathological relevance, oligopeptide transport is a subject of intense research, with implications for drug delivery, neurodegeneration, and infectious diseases. Understanding the molecular mechanisms and regulation of this process is crucial for developing targeted therapies and for interpreting the effects of genetic variants in transporter genes.
oligopeptide transport At A Glance
| GO ID | GO:0006857 |
|---|---|
| GO term | oligopeptide transport |
| Ontology | biological_process |
| Synonym | none |
| Major function | Directed movement of oligopeptides (2-20 amino acids) across membranes or within cells via transporters or pores |
| Representative transporters | SLC15 family (PepT1, PepT2, PhT1, PhT2), PTR family, Candida albicans OPT1, Chlamydia trachomatis OppA |
| Cellular locations | Plasma membrane, intracellular vesicles, bacterial inner membrane |
| Energy coupling | Proton-coupled (mammalian POTs) or sodium-coupled (some systems) |
| Physiological roles | Nutrient uptake, drug absorption, peptide hormone clearance, bacterial cell wall recycling |
What Is GO:0006857?
According to the Gene Ontology, GO:0006857 oligopeptide transport is defined as the directed movement of oligopeptides into, out of, or within a cell, or between cells, by means of some agent such as a transporter or pore. Oligopeptides are molecules that contain a small number (2 to 20) of amino-acid residues connected by peptide linkages. This definition encompasses both the transport of peptides across biological membranes and their distribution within cellular compartments, mediated by specific transport proteins.
Why Is oligopeptide transport Important in Cell Biology?
Oligopeptide transport is critically important because it governs the bioavailability of dietary peptides and peptide-based therapeutics, influences intercellular communication, and contributes to host-pathogen interactions. Dysregulation of oligopeptide transporters has been linked to neurological disorders, infectious diseases, and altered drug pharmacokinetics, making this process a key area for both basic research and translational medicine.
• Facilitates the absorption of dietary peptides and peptide-derived drugs in the intestine and kidney.
• Mediates the transport of neuroactive peptides, including amyloid-beta, in the brain, with implications for Alzheimer's disease.
• Enables bacterial pathogens to scavenge nutrients and recycle cell wall components, affecting virulence and antibiotic resistance.
• Plays a role in the uptake of antimicrobial peptides, influencing microbial susceptibility to host defense molecules.
• Contributes to glutathione homeostasis and redox balance through transporters like those in the PTR family.
• Serves as a target for improving drug delivery across biological barriers, such as the blood-brain barrier.
• Provides a mechanism for intercellular signaling via short peptide messengers.
• Is essential for the life cycle of certain fungi, such as Candida albicans, where oligopeptide transporters support growth on peptide substrates.
What Happens During oligopeptide transport?
Substrate Recognition and Binding
In simple terms: The transporter first recognizes and grabs the oligopeptide.
Oligopeptide transporters, such as those in the PTR family, possess a substrate-binding site that accommodates peptides of varying length and sequence. Structural studies have revealed that proton-coupled oligopeptide transporters (POTs) undergo conformational changes upon substrate binding, with key residues forming hydrogen bonds and electrostatic interactions with the peptide backbone. In Candida tropicalis, oligopeptide transporters specifically recognize the antimicrobial peptide CGA-N9, facilitating its transmembrane transport. The binding affinity and specificity can vary among different transporters, influencing which peptides are transported.
Conformational Cycling and Translocation
In simple terms: The transporter changes shape to move the peptide across the membrane.
Following substrate binding, oligopeptide transporters undergo a series of conformational changes that allow the peptide to be translocated across the lipid bilayer. The alternating access model describes how the transporter switches between outward-facing and inward-facing states, coupled to the movement of protons (in POTs) or sodium ions. In rat lung alveolar epithelial cells, Pept2 mediates oligopeptide transport via a proton-coupled mechanism. The energy for this process is derived from the electrochemical gradient, typically a proton gradient, which drives the uphill transport of peptides.
Substrate Release and Recycling
In simple terms: The peptide is released inside the cell, and the transporter resets.
After translocation, the oligopeptide is released into the cytoplasm or the opposing compartment, and the transporter returns to its initial conformation to begin a new cycle. In Chlamydia trachomatis, the oligopeptide transporter performs dual functions: it not only transports oligopeptides but also participates in peptidoglycan recycling, highlighting the versatility of these systems. The release step may be coupled to additional cellular processes, such as peptide degradation or utilization, ensuring efficient nutrient acquisition.
Regulation and Cellular Context
In simple terms: Cells adjust oligopeptide transport based on their needs.
Oligopeptide transport is regulated at multiple levels, including transcriptional control, post-translational modifications, and interaction with accessory proteins. In the brain, SLC15 transporters are subject to regulation that affects peptide clearance and signaling. Glutathione transporters, which are related to oligopeptide transporters, are regulated in response to oxidative stress. The activity of oligopeptide transporters can also be influenced by the availability of substrates and the metabolic state of the cell, ensuring that peptide uptake matches cellular demands.
Key Genes Involved in GO:0006857 oligopeptide transport
The following genes and proteins are key players in oligopeptide transport, as supported by published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SLC15A1 (PepT1) | Proton-coupled oligopeptide transporter in intestine and kidney | Drug absorption, nutrient uptake |
| SLC15A2 (PepT2) | High-affinity proton-coupled oligopeptide transporter in kidney, lung, brain | Peptide clearance, drug delivery |
| SLC15A3 (PhT1) | Proton-coupled histidine and dipeptide transporter | Immune function, peptide transport |
| SLC15A4 (PhT2) | Endosomal histidine and oligopeptide transporter | Autoimmunity, endosomal signaling |
| OPT1 (Candida albicans) | Oligopeptide transporter | Fungal nutrient acquisition, virulence |
| CGA-N9 transporter (Candida tropicalis) | Transports antimicrobial peptide CGA-N9 | Antifungal drug uptake |
| OppA (Chlamydia trachomatis) | Oligopeptide transporter with dual function in peptidoglycan recycling | Bacterial cell wall metabolism, pathogenesis |
| PTR family transporters | Proton-coupled peptide transport | Structural and mechanistic studies |
| Glutathione transporters | Transport of glutathione and related peptides | Redox homeostasis, detoxification |
| Aβ(1-42) transport system | Na+-coupled oligopeptide transport of amyloid-beta | Alzheimer's disease, neurodegeneration |
| Pept2 (rat) | Oligopeptide transport in lung alveolar epithelial cells | Pulmonary drug delivery |
| SLC15 family (general) | Proton-coupled oligopeptide transport | Brain peptide homeostasis |
| OPT1/OPT2 (Candida) | Oligopeptide uptake | Fungal physiology |
| PepT1/2 (mammalian) | Di- and tripeptide transport | Nutrition, pharmacology |
| PhT1/PhT2 (mammalian) | Histidine and dipeptide transport | Immunology, endosomal function |
| Opp (bacterial) | Oligopeptide permease | Bacterial nutrient uptake, virulence |
| PTR2 (plant/fungal) | Peptide transport | Nitrogen metabolism |
| DtpB (bacterial) | Di- and tripeptide transporter | Antibiotic uptake |
How Is oligopeptide transport Regulated?
Oligopeptide transport is regulated at transcriptional, post-transcriptional, and post-translational levels. In mammals, the expression of SLC15 transporters can be modulated by nutritional status, hormones, and inflammatory signals. For example, PepT1 expression in the intestine is influenced by dietary peptide availability and circadian rhythms. In the brain, SLC15A4 is regulated in response to immune challenges, affecting endosomal peptide transport. Glutathione transporters are regulated by oxidative stress through the Keap1-Nrf2 pathway. Additionally, the activity of oligopeptide transporters can be controlled by phosphorylation and interaction with regulatory proteins, although specific mechanisms vary among family members.
oligopeptide transport and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC15A2 (PepT2) | Alzheimer's disease (Aβ transport) | Knockout mice, neuronal cell lines |
| SLC15A4 (PhT2) | Autoimmune diseases, endosomal dysfunction | Knockout mice, immune cells |
| OppA (Chlamydia trachomatis) | Bacterial infection, peptidoglycan recycling | Bacterial knockout, infection models |
| OPT1 (Candida albicans) | Fungal infections | Fungal knockout, virulence assays |
| CGA-N9 transporter (Candida tropicalis) | Antifungal drug resistance | Overexpression in yeast, susceptibility tests |
Oligopeptide Transport in Neurodegeneration
Oligopeptide transporters in the brain, particularly SLC15 family members, are involved in the clearance of neuroactive peptides such as amyloid-beta (Aβ). A Na+-coupled oligopeptide transport system has been shown to mediate the transport of Aβ(1-42) in brain cells, suggesting a role in Alzheimer's disease pathogenesis. Proton-coupled oligopeptide transport in the brain is also implicated in the regulation of peptide levels and may contribute to neurodegenerative processes.
Oligopeptide Transport and Infectious Diseases
Pathogenic microorganisms utilize oligopeptide transporters for nutrient acquisition and cell wall recycling. In Chlamydia trachomatis, the oligopeptide transporter OppA performs dual functions in oligopeptide transport and peptidoglycan recycling, which are essential for bacterial survival and virulence. Candida albicans expresses an oligopeptide transport gene that supports growth on peptide substrates, contributing to its pathogenicity. Candida tropicalis oligopeptide transporters facilitate the uptake of the antimicrobial peptide CGA-N9, which can influence antifungal susceptibility.
Oligopeptide Transport in Drug Delivery and Pharmacokinetics
Oligopeptide transporters are key determinants of the absorption and distribution of peptide-based drugs. PepT1 and PepT2 mediate the uptake of various therapeutic peptides and peptidomimetics, affecting their oral bioavailability and tissue targeting. In the lung, Pept2 is responsible for oligopeptide transport in alveolar epithelial cells, which is relevant for inhaled peptide drug delivery. Understanding these transport mechanisms can aid in the design of drugs with improved pharmacokinetic profiles.
From oligopeptide transport-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does SLC15A2 mediate amyloid-beta transport in neurons? | SLC15A2 knockout and knock-in cell lines |
| What is the role of OppA in Chlamydia peptidoglycan recycling? | OppA knockout Chlamydia trachomatis |
| Can PepT2 be targeted for lung drug delivery? | Pept2 knockout rat alveolar epithelial cells |
| How does SLC15A4 regulate endosomal peptide transport? | SLC15A4 knockout macrophages |
| Does OPT1 contribute to Candida albicans virulence? | OPT1 knockout Candida albicans in infection models |
| What is the substrate specificity of CGA-N9 transporter? | Overexpression in Candida tropicalis |
How to Study the oligopeptide transport Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Radiolabeled peptide uptake | Transport activity | Characterizing PepT2 in lung cells |
| CRISPR-Cas9 knockout | Loss of transporter function | SLC15A2 knockout in neurons |
| X-ray crystallography | Three-dimensional structure | PTR family transporters |
| Immunofluorescence | Subcellular localization | SLC15A4 in endosomes |
| Growth assays on peptides | Nutrient acquisition | Candida albicans OPT1 |
| Antimicrobial peptide susceptibility | Transporter-mediated drug uptake | Candida tropicalis CGA-N9 |
| Gene expression analysis (qPCR) | Transcript levels | Regulation of oligopeptide transporters |
| Peptidoglycan recycling assays | Cell wall metabolism | Chlamydia OppA |
Transport Assays
Direct measurement of oligopeptide transport activity is typically performed using radiolabeled or fluorescently labeled peptides in cell-based assays. For example, the uptake of radiolabeled dipeptides in rat lung alveolar epithelial cells was used to characterize Pept2-mediated transport. In microbial systems, growth assays on peptide substrates or susceptibility tests with antimicrobial peptides can assess transporter function.
Genetic Knockout and Knockdown
CRISPR-Cas9 or RNA interference can be used to generate knockout or knockdown models to study the loss of function of specific oligopeptide transporters. Knockout of SLC15A2 in cell lines has been used to confirm its role in peptide transport. In bacteria, targeted gene deletion of oppA has elucidated its dual function in Chlamydia.
Structural and Biophysical Methods
X-ray crystallography and cryo-electron microscopy have provided insights into the structure of proton-coupled oligopeptide transporters, revealing the molecular basis of substrate recognition and conformational cycling. These methods are complemented by biochemical assays to measure binding affinities and transport kinetics.
Expression and Localization Studies
Quantitative PCR, Western blotting, and immunofluorescence are used to determine the expression levels and subcellular localization of oligopeptide transporters. For instance, the localization of SLC15A4 in endosomes has been studied using immunofluorescence. In Candida albicans, expression of the oligopeptide transport gene was analyzed under different growth conditions.
How CRISPR Can Be Used to Study GO:0006857 oligopeptide transport
Knockout
CRISPR-Cas9 knockout of oligopeptide transporter genes, such as SLC15A2 or OppA, allows researchers to study the consequences of loss of transport function. For example, knockout of SLC15A2 in neuronal cells can reveal its role in amyloid-beta clearance. In Chlamydia trachomatis, oppA knockout has been used to demonstrate its dual function in oligopeptide transport and peptidoglycan recycling.
Point Mutation
Introducing point mutations in transporter genes can help identify key residues involved in substrate binding or proton coupling. For instance, mutating residues in the PTR family transporters can affect transport kinetics and specificity. Such models are valuable for dissecting the molecular mechanism of oligopeptide transport.
Knock-in
Knock-in of tagged or fluorescently labeled transporters enables real-time tracking of protein localization and dynamics. For example, a GFP-tagged SLC15A4 knock-in can be used to monitor endosomal trafficking. Knock-in of disease-associated variants can also model human genetic disorders affecting oligopeptide transport.
Overexpression
Overexpression of oligopeptide transporters in cell lines or microorganisms can enhance transport capacity and facilitate biochemical studies. Overexpression of the CGA-N9 transporter in Candida tropicalis increased uptake of the antimicrobial peptide, providing a system to study its mechanism. Similarly, overexpression of PepT2 in lung cells can boost peptide transport for drug delivery studies.
How EDITGENE Supports oligopeptide transport Research
Researchers studying oligopeptide transport-related genes often need to determine whether a candidate gene is causally involved in peptide uptake, clearance, or drug response. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models, enabling functional validation of oligopeptide transporters in relevant biological contexts.
Contact EDITGENE today to design your custom CRISPR model for oligopeptide transport research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SLC15A1 Knockout Caco-2 Cell Line | EDJ-KQ10 | Human | 6564 | Details Get a Quote |
| SLC15A1 Knockout HEK293 Cell Line | EDJ-KQ5038 | Human | 6564 | Details Get a Quote |
| SLC15A2 Knockout HEK293 Cell Line | EDJ-KQ5786 | Human | 6565 | Details Get a Quote |
| SLC15A4 Knockout HEK293 Cell Line | EDJ-KQ7223 | Human | 121260 | Details Get a Quote |
| SLC15A1 Knockout HCT 116 Cell Line | EDJ-KQ29205 | Human | 6564 | Details Get a Quote |
| SLC15A2 Knockout HCT 116 Cell Line | EDJ-KQ29206 | Human | 6565 | Details Get a Quote |
| SLC15A1 Knockout HeLa Cell Line | EDJ-KQ18244 | Human | 6564 | Details Get a Quote |
| SLC15A4 Knockout A-549 Cell Line | EDJ-KQ33514 | Human | 121260 | Details Get a Quote |
| SLC15A4 Knockout HCT 116 Cell Line | EDC09911 | Human | 121260 | Details Get a Quote |
| SLC15A4 Knockout HeLa Cell Line | EDJ-KQ33517 | Human | 121260 | Details Get a Quote |
| SLC15A2 Knockout HeLa Cell Line | EDJ-KQ54510 | Human | 6565 | Details Get a Quote |
| SLC15A1 Knockout A-549 Cell Line | EDJ-KQ62995 | Human | 6564 | Details Get a Quote |
| SLC15A2 Knockout A-549 Cell Line | EDJ-KQ62996 | Human | 6565 | Details Get a Quote |
| SLC15A1 Knockout Huh-7 Cell Line | EDC07819 | Human | 6564 | Details Get a Quote |
| SLC15A4 Overexpression THP-1 Stable Cell Line | EDJ-GQ119 | Human | 121260 | Details Get a Quote |
Displaying Records 1 To 15 Of 15 Records
Frequently Asked Questions About oligopeptide transport
What is oligopeptide transport?
Oligopeptide transport is the directed movement of short peptides (2-20 amino acids) across cellular membranes or within cells, mediated by transporters or pores.
What genes are involved in oligopeptide transport?
Key genes include SLC15A1 (PepT1), SLC15A2 (PepT2), SLC15A3 (PhT1), SLC15A4 (PhT2), and microbial transporters such as OPT1 in Candida albicans and OppA in Chlamydia trachomatis.
How does oligopeptide transport work?
Most oligopeptide transporters use an alternating access mechanism coupled to proton or sodium gradients to move peptides across membranes.
Why is oligopeptide transport important for drug delivery?
It mediates the absorption of peptide-based drugs in the intestine, kidney, and lung, influencing their bioavailability and tissue distribution.
What diseases are associated with oligopeptide transport?
Dysregulation of oligopeptide transporters has been linked to Alzheimer's disease, autoimmune disorders, and bacterial infections.
How can I study oligopeptide transport using CRISPR?
CRISPR knockout, knock-in, and overexpression models allow functional dissection of transporter genes in cell lines and animal models.
What is the role of SLC15A2 in the brain?
SLC15A2 (PepT2) is involved in the transport of neuroactive peptides, including amyloid-beta, and may contribute to Alzheimer's disease.
Which model system is best for studying oligopeptide transport?
The choice depends on the research question: mammalian cell lines for human transporters, yeast for fungal transporters, and bacterial strains for microbial transporters.
Can oligopeptide transporters be targeted for antimicrobial therapy?
Yes, microbial oligopeptide transporters are potential drug targets because they are essential for nutrient acquisition and virulence.
What methods are used to measure oligopeptide transport?
Common methods include radiolabeled peptide uptake assays, fluorescent peptide transport, and genetic knockout studies.
Conclusion
Oligopeptide transport (GO:0006857) is a vital biological process that impacts nutrient uptake, drug delivery, and host-pathogen interactions. The SLC15 family and related transporters are central to these functions, with roles in brain peptide homeostasis, intestinal absorption, and microbial virulence. Dysregulation of oligopeptide transport is implicated in neurodegenerative diseases, infections, and altered drug responses, making it a compelling target for therapeutic intervention. Advances in CRISPR-based genome editing have revolutionized the study of oligopeptide transporters, enabling precise knockout, knock-in, and overexpression models. These tools allow researchers to dissect the molecular mechanisms, regulation, and disease relevance of oligopeptide transport, paving the way for novel diagnostics and treatments. EDITGENE's comprehensive services support these efforts, providing custom cell models and screening platforms to accelerate discovery in this field.
References
- 1. Xiang J et al.. 2023. Proton-Coupled Oligopeptide Transport (Slc15) in the Brain: Past and Future Research.. Pharm Res 40(11):2533-2540 PMID: 37308743
- 2. Wu J et al.. 2023. Candida tropicalis oligopeptide transporters assist in the transmembrane transport of the antimicrobial peptide CGA-N9.. Biochem Biophys Res Commun 649:101-109 PMID: 36764112
- 3. Newstead S. 2015. Molecular insights into proton coupled peptide transport in the PTR family of oligopeptide transporters.. Biochim Biophys Acta 1850(3):488-99 PMID: 24859687
- 4. Gukasyan HJ et al.. 2017. Oligopeptide Transport in Rat Lung Alveolar Epithelial Cells is Mediated by Pept2.. Pharm Res 34(12):2488-2497 PMID: 28831683
- 5. Singh R et al.. 2020. Chlamydia trachomatis Oligopeptide Transporter Performs Dual Functions of Oligopeptide Transport and Peptidoglycan Recycling.. Infect Immun 88(5) PMID: 32094256
- 6. Bachhawat AK et al.. 2013. Glutathione transporters.. Biochim Biophys Acta 1830(5):3154-64 PMID: 23206830
- 7. Lubkowitz MA et al.. 1997. An oligopeptide transport gene from Candida albicans.. Microbiology (Reading) 143 ( Pt 2):387-396 PMID: 9043116
- 8. Higuchi K et al.. 2020. Involvement of a Na(+)-coupled Oligopeptide Transport System for β-amyloid Peptide (Aβ(1-42)) in Brain Cells.. Pharm Res 37(6):98 PMID: 32419062
