GO:0015888 thiamine transport: Vitamin B1 Uptake Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0015888 (thiamine transport) describes the directed movement of thiamine (vitamin B1) into, out of, or within a cell via transporters or pores.
• The process is mediated by solute carrier transporters, principally SLC19A2 (THTR1), SLC19A3 (THTR2), and SLC25A19, which move thiamine across plasma and mitochondrial membranes.
• Intestinal thiamine absorption occurs through a saturable, sodium-independent carrier mechanism at low concentrations and passive diffusion at high concentrations.
• Genetic defects in thiamine transport cause severe neurological disorders including thiamine-responsive megaloblastic anemia (SLC19A2), biotin-responsive basal ganglia disease (SLC19A3), and Amish microcephaly (SLC25A19).
• High-dose thiamine supplementation can rescue or ameliorate phenotypes in several transport defects, making these genes attractive therapeutic targets.
• CRISPR knockout, point-mutation, and knock-in models are essential tools for dissecting transporter-specific contributions to thiamine homeostasis and disease.
Description
Thiamine (vitamin B1) is a water-soluble vitamin that serves as an essential cofactor for enzymes involved in carbohydrate metabolism, branched-chain amino acid catabolism, and the pentose phosphate pathway. Because humans cannot synthesize thiamine, they depend entirely on dietary intake and efficient transport across cellular membranes. The Gene Ontology term GO:0015888, thiamine transport, captures the directed movement of this vitamin into, out of, or within a cell by means of transporters or pores. Understanding this process at the molecular level is critical because impaired thiamine transport underlies a spectrum of neurological and hematological diseases. The transport of thiamine is mediated by specific solute carrier (SLC) proteins that recognize the vitamin with high affinity and translocate it across lipid bilayers. These transporters are expressed in a tissue-specific manner: SLC19A2 and SLC19A3 are prominent in the intestine, kidney, and brain, while SLC25A19 localizes to mitochondria. The directed movement of thiamine is not merely a passive diffusion process; it involves conformational changes in the transporter, substrate recognition, and in some cases, proton or sodium coupling. For researchers, GO:0015888 provides a framework for studying vitamin homeostasis, transporter pharmacology, and disease mechanisms. Mutations in thiamine transporters cause rare but devastating conditions, and the transporters are also targets for drug interactions, including the anticancer drug fedratinib. This article synthesizes the current understanding of thiamine transport, its genetic players, and the experimental models used to study it.
thiamine transport At A Glance
| GO ID | GO:0015888 |
|---|---|
| GO term | thiamine transport |
| Ontology | biological_process |
| Synonym | thiamin transport; vitamin B1 transport |
| Major function | Directed movement of thiamine (vitamin B1) across cellular membranes via transporters or pores |
| Key transporters | SLC19A2 (THTR1), SLC19A3 (THTR2), SLC25A19 |
| Tissue distribution | Intestine, kidney, brain, liver, and mitochondria |
| Associated diseases | Thiamine-responsive megaloblastic anemia, biotin-responsive basal ganglia disease, Amish microcephaly |
| Therapeutic relevance | High-dose thiamine supplementation and transporter-targeted drugs |
What Is GO:0015888?
GO:0015888 (thiamine transport) is defined as the directed movement of thiamine into, out of, or within a cell, or between cells, by means of some agent such as a transporter or pore. Thiamine is vitamin B1, a water-soluble vitamin present in fresh vegetables and meats, especially liver. The term encompasses all cellular routes of thiamine translocation, including intestinal absorption, renal reabsorption, blood-brain barrier crossing, and mitochondrial import. It is a biological process that depends on specific membrane proteins, primarily the SLC19 and SLC25 families.
Why Is thiamine transport Important in Cell Biology?
Thiamine transport is essential for maintaining cellular energy metabolism and neurological function, as thiamine pyrophosphate (TPP) is a cofactor for pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase, and transketolase. Defects in transport lead to thiamine deficiency at the cellular level even when systemic levels are normal, causing severe diseases such as Wernicke encephalopathy, beriberi, and genetic disorders like thiamine-responsive megaloblastic anemia. Moreover, thiamine transporters influence drug pharmacokinetics, as exemplified by the interaction between SLC19A2/A3 and fedratinib. Therefore, studying GO:0015888 is directly relevant to neurobiology, hematology, nutrition, and pharmacology.
• Thiamine transport is required for intestinal absorption of vitamin B1 and its delivery to tissues.
• SLC19A2 mutations cause thiamine-responsive megaloblastic anemia with diabetes and deafness.
• SLC19A3 mutations lead to biotin-responsive basal ganglia disease, a treatable neurodegeneration.
• SLC25A19 mutations cause Amish microcephaly and severe neurological impairment.
• Thiamine transporters are targets for drug interactions, affecting cancer therapy.
• Impaired thiamine transport contributes to Wernicke-Korsakoff syndrome in alcoholics.
• Thiamine transport is critical for placental and blood-brain barrier function.
• Understanding transport mechanisms aids in designing vitamin-based therapies.
• Transporters are potential biomarkers for thiamine-related metabolic disorders.
• CRISPR models of transporter genes enable causal testing of disease variants.
What Happens During thiamine transport?
Substrate recognition and binding
In simple terms: The transporter protein grabs thiamine from one side of the membrane.
Thiamine transport begins with the specific recognition of thiamine by a membrane transporter, such as SLC19A2 or SLC19A3. Structural studies reveal that these transporters possess a binding pocket that accommodates the pyrimidine and thiazolium rings of thiamine, with key residues forming hydrogen bonds and hydrophobic interactions. The binding is saturable and exhibits high affinity, with Km values in the micromolar range. This step ensures selectivity against structurally related compounds, although some drugs like fedratinib can compete for the same site.
Conformational change and translocation
In simple terms: The transporter changes shape to move thiamine across the membrane.
Upon substrate binding, the transporter undergoes a conformational change that exposes the bound thiamine to the opposite side of the membrane. This alternating-access mechanism is typical of solute carriers and does not require ATP hydrolysis directly, although it can be driven by electrochemical gradients. For SLC19A3, structural analyses have captured inward-facing and outward-facing states, providing a molecular movie of the transport cycle. The translocation step is rate-limiting and can be modulated by mutations that alter protein dynamics.
Intestinal absorption
In simple terms: Thiamine from food is taken up by the gut.
In the intestine, thiamine absorption occurs via a dual mechanism: at low (physiological) concentrations, a saturable, sodium-independent carrier-mediated process predominates, while at high concentrations, passive diffusion contributes. The carrier is likely SLC19A2 or SLC19A3, which are expressed on the apical membrane of enterocytes. This process is regulated by thiamine status and can be upregulated in deficiency. Intestinal transport is the first step in delivering vitamin B1 to the bloodstream.
Renal reabsorption and tissue distribution
In simple terms: The kidney reclaims thiamine to prevent loss in urine.
After filtration, thiamine is reabsorbed in the renal proximal tubule by SLC19A2 and SLC19A3. This active reabsorption is crucial for maintaining systemic thiamine levels, as the kidney can excrete excess but conserves the vitamin under normal conditions. Transporters in the blood-brain barrier and placenta also mediate thiamine delivery to the brain and fetus, respectively. Tissue-specific expression patterns determine the distribution of thiamine to high-demand organs like the brain and heart.
Mitochondrial thiamine import
In simple terms: Thiamine gets into mitochondria to be converted into its active form.
Inside cells, thiamine must enter mitochondria to be phosphorylated to thiamine pyrophosphate (TPP), the active cofactor. SLC25A19 is the mitochondrial thiamine pyrophosphate carrier that imports TPP into the mitochondrial matrix. Defects in SLC25A19 cause Amish microcephaly, highlighting the importance of this step. Mitochondrial transport is distinct from plasma membrane transport and is essential for oxidative metabolism.
Key Genes Involved in GO:0015888 thiamine transport
The following genes encode proteins that directly mediate or regulate thiamine transport across cellular membranes.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SLC19A2 | High-affinity thiamine transporter (THTR1) at plasma membrane | Mutations cause thiamine-responsive megaloblastic anemia; drug interaction studies |
| SLC19A3 | Thiamine transporter (THTR2) in intestine, kidney, brain | Mutations cause biotin-responsive basal ganglia disease; structural studies |
| SLC25A19 | Mitochondrial thiamine pyrophosphate carrier | Mutations cause Amish microcephaly and neuropathy |
| SLC19A1 | Reduced folate carrier; can transport thiamine analogs | Broad substrate specificity; potential off-target effects |
| SLC22A1 | Organic cation transporter; may contribute to thiamine uptake | Less characterized; possible role in tissue distribution |
| SLC22A2 | Organic cation transporter; thiamine transport in kidney | Renal handling of thiamine |
| SLC22A3 | Organic cation transporter; thiamine transport in brain | Blood-brain barrier transport |
| SLC44A1 | Choline transporter-like protein; may transport thiamine | Emerging evidence for alternative transporters |
| SLC44A2 | Choline transporter-like protein; thiamine transport | Potential role in inner ear and brain |
| SLC44A4 | Choline transporter-like protein; thiamine transport | Intestinal and renal expression |
| SLC46A1 | Heme carrier; may transport thiamine | Overlap with folate transport |
| SLC46A2 | Heme carrier; thiamine transport | Less studied |
| SLC46A3 | Heme carrier; thiamine transport | Potential role in lysosomes |
| SLC7A5 | L-type amino acid transporter; thiamine transport | Broad specificity |
| SLC7A8 | L-type amino acid transporter; thiamine transport | Intestinal absorption |
| SLC16A1 | Monocarboxylate transporter; thiamine transport | Metabolic coupling |
| SLC16A2 | Monocarboxylate transporter; thiamine transport | Brain transport |
| SLC6A1 | GABA transporter; thiamine transport | Neurotransmitter overlap |
How Is thiamine transport Regulated?
Thiamine transport is regulated at multiple levels. At the transcriptional level, expression of SLC19A2 and SLC19A3 can be modulated by thiamine availability, with deficiency leading to upregulation. Post-translational regulation includes phosphorylation and trafficking of transporters to the plasma membrane. Hormonal signals such as insulin may influence thiamine transport in diabetes. Additionally, drug interactions, such as fedratinib inhibition of SLC19A2/A3, provide a pharmacological layer of regulation. The process is also subject to feedback inhibition by intracellular thiamine pyrophosphate levels.
thiamine transport and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC19A2 | Thiamine-responsive megaloblastic anemia | Knockout HEK293 cells; patient-derived iPSCs |
| SLC19A3 | Biotin-responsive basal ganglia disease | Knockout neurons; knock-in mutant mice |
| SLC25A19 | Amish microcephaly | Mitochondrial import assays in KO cells |
| SLC19A2/A3 | Drug-induced thiamine deficiency (fedratinib) | Competition binding assays; transporter overexpression |
| SLC19A3 | Neurodegeneration with brain iron accumulation | Patient fibroblasts; CRISPR-corrected lines |
Thiamine-responsive megaloblastic anemia syndrome
Mutations in SLC19A2 cause thiamine-responsive megaloblastic anemia (TRMA), characterized by megaloblastic anemia, diabetes mellitus, and sensorineural deafness. The disease is inherited in an autosomal recessive pattern, and high-dose thiamine supplementation can partially correct the hematological and metabolic abnormalities. This condition directly links GO:0015888 to human pathology, as defective transport leads to cellular thiamine deficiency.
Biotin-responsive basal ganglia disease
SLC19A3 mutations cause biotin-responsive basal ganglia disease (BBGD), also known as thiamine metabolism dysfunction syndrome-2. Patients present with subacute encephalopathy, dystonia, and seizures, often triggered by febrile illness. Treatment with high-dose biotin and thiamine can reverse symptoms, underscoring the role of thiamine transport in neuronal survival. This disorder highlights the brain's dependence on efficient thiamine uptake.
Amish microcephaly and mitochondrial thiamine transport
SLC25A19 mutations cause Amish microcephaly, a severe neurological disorder with alpha-ketoglutaric aciduria and early death. The defect impairs mitochondrial thiamine pyrophosphate import, leading to energy failure in the brain. This condition demonstrates the importance of mitochondrial thiamine transport for neurodevelopment.
Thiamine transport in cancer and drug interactions
Thiamine transporters are expressed in various cancers and can influence drug sensitivity. Fedratinib, a JAK2 inhibitor used in myelofibrosis, inhibits SLC19A2 and SLC19A3, causing thiamine deficiency and Wernicke encephalopathy. This drug interaction illustrates the clinical relevance of thiamine transport in oncology and the need for monitoring.
From thiamine transport-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of SLC19A2 impair thiamine uptake? | SLC19A2 knockout HEK293 or HeLa cells |
| How do disease mutations affect transporter function? | Point-mutation knock-in of SLC19A3 variants |
| Can wild-type transporter rescue a disease phenotype? | Knock-in of SLC19A2 into patient iPSCs |
| Where is the transporter localized? | Tagged knock-in of SLC19A3 with GFP |
| Does overexpression alter drug sensitivity? | SLC19A2/A3 overexpression in cancer cell lines |
| What is the role of SLC25A19 in mitochondria? | SLC25A19 knockout and mitochondrial import assays |
How to Study the thiamine transport Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Radioactive uptake assay | Transport rate and kinetics | Comparing wild-type and mutant transporters |
| Cryo-EM | 3D structure and conformational states | Drug binding site mapping |
| CRISPR knockout screen | Genes affecting thiamine transport | Identifying novel transporters |
| RNA-seq | Transporter mRNA expression | Tissue distribution and regulation |
| Proteomics | Protein abundance and modifications | Post-translational regulation |
| Site-directed mutagenesis | Functional impact of specific residues | Validating structural models |
| Patient-derived iPSCs | Disease modeling and drug response | Personalized therapy testing |
| In vivo microdialysis | Extracellular thiamine levels | Brain thiamine dynamics |
Radioactive thiamine uptake assays
Uptake assays using radiolabeled thiamine (3H-thiamine) are the gold standard for measuring transport activity in cells and membrane vesicles. These assays quantify the rate of thiamine internalization and can determine kinetic parameters such as Km and Vmax. They are used to compare wild-type and mutant transporters and to test inhibitors like fedratinib.
Structural biology (cryo-EM and X-ray crystallography)
Cryo-electron microscopy and X-ray crystallography have resolved the structures of SLC19A2 and SLC19A3, revealing the binding pocket and conformational states. These methods provide atomic-level insights into substrate recognition and drug binding, guiding mutagenesis studies. Structural data are essential for understanding how disease mutations disrupt transport.
CRISPR-based genetic screens
Genome-wide CRISPR knockout screens can identify genes that modulate thiamine transport or sensitivity to thiamine analogs. Such screens have uncovered alternative transporters and regulatory factors. They are powerful for discovering synthetic lethal interactions in cancer cells with transporter defects.
Transcriptomics and proteomics
RNA-seq and quantitative proteomics measure expression levels of thiamine transporters across tissues and conditions. These approaches reveal tissue-specific expression patterns and regulation by thiamine status. They can also identify splicing variants and post-translational modifications.
How CRISPR Can Be Used to Study GO:0015888 thiamine transport
Knockout
CRISPR knockout of SLC19A2, SLC19A3, or SLC25A19 in cell lines such as HEK293 or HeLa abolishes thiamine transport, providing a clean background to study transporter function. These knockout models are used to measure residual uptake, test compensatory transporters, and assess drug sensitivity. Knockout mice for SLC19A3 exhibit neurological phenotypes resembling biotin-responsive basal ganglia disease.
Point Mutation
CRISPR point mutation introduces disease-associated missense variants into endogenous transporter genes, allowing study of their functional impact in a physiological context. For example, knock-in of SLC19A3 mutations found in patients can reveal defects in substrate binding or trafficking. This approach is superior to overexpression because it preserves native regulation.
Knock-in
Knock-in of tagged transporters (e.g., GFP-SLC19A3) enables live-cell imaging and localization studies. Knock-in of wild-type SLC19A2 into patient iPSCs can rescue disease phenotypes, validating causality. This strategy is also used to create reporter lines for high-throughput screening.
Overexpression
Overexpression of SLC19A2 or SLC19A3 in cancer cell lines increases thiamine uptake and can alter sensitivity to antifolate drugs. Overexpression models are useful for drug interaction studies and for producing large amounts of transporter protein for structural analysis. They also help identify off-target effects of inhibitors.
How EDITGENE Supports thiamine transport Research
Researchers studying thiamine transport-related genes often need to determine whether a candidate gene is causally involved in vitamin B1 homeostasis, disease pathogenesis, or drug response. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models that answer these questions.
Contact EDITGENE today to design your custom CRISPR model for thiamine transport research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SLC35F3 Knockout HEK293 Cell Line | EDJ-KQ2105 | Human | 148641 | Details Get a Quote |
| SLC22A1 Knockout HEK293 Cell Line | EDJ-KQ5796 | Human | 6580 | Details Get a Quote |
| SLC19A2 Knockout HEK293 Cell Line | EDJ-KQ7089 | Human | 10560 | Details Get a Quote |
| SLC19A3 Knockout HEK293 Cell Line | EDJ-KQ9546 | Human | 80704 | Details Get a Quote |
| SLC22A1 Knockout A-549 Cell Line | EDJ-KQ29210 | Human | 6580 | Details Get a Quote |
| SLC19A2 Knockout A-549 Cell Line | EDJ-KQ31933 | Human | 10560 | Details Get a Quote |
| SLC19A2 Knockout HCT 116 Cell Line | EDJ-KQ31934 | Human | 10560 | Details Get a Quote |
| SLC19A2 Knockout HeLa Cell Line | EDJ-KQ31935 | Human | 10560 | Details Get a Quote |
| SLC35F3 Knockout A-549 Cell Line | EDJ-KQ22225 | Human | 148641 | Details Get a Quote |
| SLC35F3 Knockout HCT 116 Cell Line | EDJ-KQ22226 | Human | 148641 | Details Get a Quote |
| SLC35F3 Knockout HeLa Cell Line | EDJ-KQ22227 | Human | 148641 | Details Get a Quote |
| SLC19A3 Knockout A-549 Cell Line | EDJ-KQ36334 | Human | 80704 | Details Get a Quote |
| SLC22A1 Knockout HeLa Cell Line | EDJ-KQ54519 | Human | 6580 | Details Get a Quote |
| SLC19A3 Knockout HeLa Cell Line | EDJ-KQ57335 | Human | 80704 | Details Get a Quote |
| SLC22A1 Knockout HCT 116 Cell Line | EDJ-KQ71475 | Human | 6580 | Details Get a Quote |
Displaying Records 1 To 15 Of 16 Records
Frequently Asked Questions About thiamine transport
What is GO:0015888 thiamine transport?
GO:0015888 is a Gene Ontology biological process term describing the directed movement of thiamine (vitamin B1) into, out of, or within a cell via transporters or pores.
What genes are involved in thiamine transport?
Key genes include SLC19A2, SLC19A3, and SLC25A19, which encode transporters for thiamine across plasma and mitochondrial membranes.
What diseases are caused by defective thiamine transport?
Mutations in SLC19A2 cause thiamine-responsive megaloblastic anemia, SLC19A3 mutations cause biotin-responsive basal ganglia disease, and SLC25A19 mutations cause Amish microcephaly.
How is thiamine absorbed in the intestine?
Thiamine is absorbed via a saturable carrier-mediated mechanism at low concentrations and passive diffusion at high concentrations.
What is the role of SLC19A3 in the brain?
SLC19A3 transports thiamine across the blood-brain barrier and into neurons, and its dysfunction leads to neurodegeneration.
Can thiamine supplementation treat transport defects?
Yes, high-dose thiamine can partially rescue symptoms in thiamine-responsive megaloblastic anemia and biotin-responsive basal ganglia disease.
How do researchers study thiamine transport?
Common methods include radioactive uptake assays, cryo-EM, CRISPR knockout screens, and transcriptomics.
What drugs interact with thiamine transporters?
Fedratinib inhibits SLC19A2 and SLC19A3, potentially causing thiamine deficiency and Wernicke encephalopathy.
What is the mitochondrial thiamine transporter?
SLC25A19 is the mitochondrial thiamine pyrophosphate carrier essential for oxidative metabolism.
How can CRISPR help study thiamine transport?
CRISPR knockout, point mutation, and knock-in models allow causal testing of transporter genes in disease and drug response.
Conclusion
Thiamine transport (GO:0015888) is a fundamental biological process that ensures cellular supply of vitamin B1 for energy metabolism and neurological function. The identification of specific transporters like SLC19A2, SLC19A3, and SLC25A19 has illuminated the molecular basis of thiamine-related diseases and drug interactions. Continued research using CRISPR models and structural biology will further unravel the complexities of this pathway and enable targeted therapies.
References
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- 2. Brown G. 2014. Defects of thiamine transport and metabolism.. J Inherit Metab Dis 37(4):577-85 PMID: 24789339
- 3. Rindi G et al.. 2000. Thiamine intestinal transport and related issues: recent aspects.. Proc Soc Exp Biol Med 224(4):246-55 PMID: 10964259
- 4. Rindi G et al.. 1972. Thiamine intestinal transport.. Physiol Rev 52(4):821-7 PMID: 4563896
- 5. Xian X et al.. 2018. [Defect of thiamine transport and activation and related disease].. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 35(1):121-124 PMID: 29419877
- 6. Ortigoza-Escobar JD et al.. 2016. Treatment of genetic defects of thiamine transport and metabolism.. Expert Rev Neurother 16(7):755-63 PMID: 27191787
- 7. Gabriel F et al.. 2024. Structural basis of thiamine transport and drug recognition by SLC19A3.. Nat Commun 15(1):8542 PMID: 39358356
- 8. Marcé-Grau A et al.. 2019. Genetic defects of thiamine transport and metabolism: A review of clinical phenotypes, genetics, and functional studies.. J Inherit Metab Dis 42(4):581-597 PMID: 31095747
