GO:0008523 sodium-dependent multivitamin transmembrane transporter activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0008523 describes a sodium-coupled transporter activity that moves multivitamins such as pantothenate, biotin and lipoate across membranes.
• The activity is mediated by the sodium-dependent multivitamin transporter (SMVT), encoded by SLC5A6 in mammals.
• SMVT couples the inward transport of pantothenate, biotin and lipoate to the sodium gradient, making it a secondary active transporter.
• Loss or dysfunction of this activity can impair cellular uptake of essential vitamins, affecting metabolism, growth and development.
• Experimental study of GO:0008523 uses transport assays, radiolabeled substrates, electrophysiology and CRISPR-based genetic models.
• CRISPR knockout, point mutation, knock-in and overexpression models enable causal dissection of SMVT function in health and disease.
Description
GO:0008523, sodium-dependent multivitamin transmembrane transporter activity, is a molecular function that enables the sodium-coupled transfer of multivitamins, including pantothenate, biotin and lipoate, across biological membranes. This activity is essential for cellular uptake of water-soluble vitamins that cannot freely diffuse through lipid bilayers. The transporter responsible, known as the sodium-dependent multivitamin transporter (SMVT), was cloned and functionally expressed from mammalian cells, revealing its ability to mediate the uptake of pantothenate, biotin and lipoate in a sodium-dependent manner. Researchers study GO:0008523 to understand vitamin homeostasis, energy metabolism, and the pathophysiology of vitamin deficiency states. Because these vitamins serve as cofactors for carboxylases and other enzymes, altered transporter activity can have broad metabolic consequences. The term is therefore central to nutrition, cell biology and metabolic disease research.
sodium-dependent multivitamin transmembrane transporter activity At A Glance
| GO ID | GO:0008523 |
|---|---|
| GO term | sodium-dependent multivitamin transmembrane transporter activity |
| Ontology | molecular_function |
| Synonym | none |
| Major function | Sodium-coupled transport of pantothenate, biotin and lipoate across membranes |
| Reaction | multivitamin(out) + Na+(out) = multivitamin(in) + Na+(in) |
| Substrates | Pantothenate, biotin, lipoate |
| Cofactor | Sodium ions |
| Representative gene | SLC5A6 (SMVT) |
What Is GO:0008523?
GO:0008523 describes a transporter activity that moves a multivitamin molecule from one side of a membrane to the other together with sodium ions, following the reaction: multivitamin(out) + Na+(out) = multivitamin(in) + Na+(in). The multivitamins handled by this activity include pantothenate (vitamin B5), biotin (vitamin B7) and lipoate (lipoic acid). In practice, this means the transporter uses the electrochemical sodium gradient to drive the accumulation of these vitamins inside cells.
Why Is sodium-dependent multivitamin transmembrane transporter activity Important in Cell Biology?
GO:0008523 is important because it controls the cellular entry of three essential vitamins that serve as cofactors for key metabolic enzymes, and its dysfunction can lead to vitamin-responsive metabolic disorders. Understanding this activity helps explain how cells maintain vitamin homeostasis and how defects contribute to disease.
• Provides a route for cellular uptake of pantothenate, biotin and lipoate.
• Links sodium gradient energy to vitamin accumulation.
• Supports cofactor supply for carboxylase enzymes.
• Relevant to nutritional deficiency and metabolic disorders.
• Target for studying transporter structure-function relationships.
• Enables experimental dissection using radiolabeled substrates.
• Contributes to understanding of epithelial transport in intestine and kidney.
• Potential therapeutic target for modulating vitamin availability.
• Model for secondary active transport mechanisms.
• Guides CRISPR-based disease modeling of vitamin transport defects.
What Happens During sodium-dependent multivitamin transmembrane transporter activity?
Sodium binding and substrate recognition
In simple terms: The transporter first grabs sodium ions and a vitamin molecule.
The sodium-dependent multivitamin transporter binds sodium ions and a multivitamin substrate such as pantothenate, biotin or lipoate. This binding is required for subsequent transport steps.
Conformational change and translocation
In simple terms: The transporter changes shape to move the vitamin across the membrane.
Upon binding, the transporter undergoes conformational changes that translocate the vitamin and sodium ions from the extracellular side to the intracellular side. This process is driven by the sodium gradient.
Release of substrates inside the cell
In simple terms: The vitamin and sodium are released inside the cell.
After translocation, the multivitamin and sodium ions are released into the cytoplasm, allowing the vitamin to participate in metabolic pathways.
Reset of the transporter
In simple terms: The transporter returns to its original shape to start again.
The transporter reorients to its initial conformation, ready for another transport cycle, maintaining a continuous supply of vitamins when the sodium gradient is present.
Key Genes Involved in GO:0008523 sodium-dependent multivitamin transmembrane transporter activity
The following genes and proteins are directly or functionally associated with sodium-dependent multivitamin transmembrane transporter activity.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SLC5A6 | Encodes the sodium-dependent multivitamin transporter (SMVT) | Primary gene for GO:0008523; studied for pantothenate, biotin and lipoate uptake |
| SLC5A1 | Sodium-glucose cotransporter | Related sodium-coupled transporter for comparative studies |
| SLC5A2 | Sodium-glucose cotransporter | Related sodium-coupled transporter for comparative studies |
| SLC6A19 | Sodium-dependent amino acid transporter | Related sodium-coupled transporter for comparative studies |
| SLC7A11 | Cystine/glutamate antiporter | Not sodium-dependent but involved in nutrient transport |
| SLC3A2 | Chaperone for amino acid transporters | Related to membrane transport processes |
| SLC25A1 | Mitochondrial citrate carrier | Indirectly linked to biotin metabolism |
| HLCS | Holocarboxylase synthetase | Uses biotin for carboxylase activation |
| PC | Pyruvate carboxylase | Biotin-dependent enzyme |
| ACACA | Acetyl-CoA carboxylase alpha | Biotin-dependent enzyme |
| ACACB | Acetyl-CoA carboxylase beta | Biotin-dependent enzyme |
| MCCC1 | Methylcrotonoyl-CoA carboxylase subunit | Biotin-dependent enzyme |
| MCCC2 | Methylcrotonoyl-CoA carboxylase subunit | Biotin-dependent enzyme |
| PCCA | Propionyl-CoA carboxylase alpha | Biotin-dependent enzyme |
| PCCB | Propionyl-CoA carboxylase beta | Biotin-dependent enzyme |
| PDHX | Pyruvate dehydrogenase complex component | Lipoate-dependent enzyme |
| DLD | Dihydrolipoamide dehydrogenase | Lipoate-dependent enzyme |
| LIAS | Lipoyl synthase | Involved in lipoate metabolism |
How Is sodium-dependent multivitamin transmembrane transporter activity Regulated?
The activity of the sodium-dependent multivitamin transporter is regulated by substrate availability and sodium gradient, and its expression can be modulated by nutritional status and hormonal signals. However, specific regulatory pathways such as mTOR or ISR have not been directly linked to GO:0008523 in the provided literature.
sodium-dependent multivitamin transmembrane transporter activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC5A6 | Biotin and pantothenate deficiency | Knockout cell line and transport assays |
| HLCS | Holocarboxylase synthetase deficiency | Point mutation knock-in models |
| PC | Pyruvate carboxylase deficiency | Overexpression and knockout models |
| PCCA | Propionic acidemia | Knockout and point mutation models |
| PCCB | Propionic acidemia | Knockout and point mutation models |
Vitamin deficiency disorders
Impaired sodium-dependent multivitamin transporter activity can lead to deficiencies in pantothenate, biotin and lipoate, which may cause metabolic and neurological symptoms. Studies of SMVT function help explain how mutations or altered expression contribute to these conditions.
Metabolic disorders
Because biotin and lipoate are cofactors for carboxylases and dehydrogenase complexes, defective transport can disrupt energy metabolism and lead to organic acidurias. Research on GO:0008523 provides insight into these metabolic pathways.
Cancer and cell proliferation
Rapidly dividing cells have high demand for vitamins; altered multivitamin transport may support tumor growth, making this activity a potential area of cancer metabolism research. However, direct evidence from the provided citations is limited.
From sodium-dependent multivitamin transmembrane transporter activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of SMVT abolish multivitamin uptake? | SLC5A6 knockout cell line |
| Which residues are required for sodium coupling? | Point mutation knock-in of SLC5A6 |
| Can tagged SMVT be used for localization studies? | Tagged knock-in of SLC5A6 |
| Does overexpression increase vitamin transport? | SLC5A6 overexpression cell line |
| What is the effect of SMVT on metabolic flux? | Knockout plus metabolomics |
| Can CRISPR screening identify modifiers of transport? | CRISPR library screening |
How to Study the sodium-dependent multivitamin transmembrane transporter activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Radiolabeled uptake assay | Sodium-dependent transport of vitamins | Quantifying SMVT activity |
| Electrophysiology | Ion currents and transporter kinetics | Studying sodium coupling |
| CRISPR knockout screen | Genes required for transport | Identifying modifiers |
| Metabolomics | Vitamin and metabolite levels | Assessing metabolic impact |
| Proteomics | Protein expression changes | Validating pathway effects |
| Immunofluorescence | Subcellular localization | Confirming membrane expression |
| Western blot | Protein abundance | Checking knockout/overexpression |
| qPCR | mRNA expression | Measuring SLC5A6 levels |
Transport assays with radiolabeled substrates
Uptake of radiolabeled pantothenate, biotin or lipoate can be measured in cells expressing SMVT to quantify sodium-dependent transport activity.
Electrophysiology
Electrophysiological recordings can detect sodium currents associated with transporter activity, providing real-time kinetic information.
CRISPR-based genetic screens
Genome-wide CRISPR knockout or activation screens can identify genes that regulate or are required for multivitamin transport.
Metabolomics and proteomics
Mass spectrometry-based metabolomics and proteomics can assess downstream effects of altered transporter activity on vitamin-dependent pathways.
How CRISPR Can Be Used to Study GO:0008523 sodium-dependent multivitamin transmembrane transporter activity
Knockout
CRISPR knockout of SLC5A6 can eliminate sodium-dependent multivitamin transport, providing a clean background to study its role in vitamin uptake and metabolism.
Point Mutation
Introducing point mutations in SLC5A6 allows structure-function analysis of residues critical for sodium binding or substrate recognition.
Knock-in
Knock-in of tagged SMVT (e.g., GFP or HA) enables visualization and biochemical isolation of the transporter in its native context.
Overexpression
Overexpression of SLC5A6 increases transport capacity, useful for kinetic studies and for testing whether elevated vitamin uptake alters cellular phenotypes.
How EDITGENE Supports sodium-dependent multivitamin transmembrane transporter activity Research
Researchers studying sodium-dependent multivitamin transmembrane transporter activity-related genes often need to determine whether a candidate gene is causally involved in vitamin transport, metabolic regulation, or disease. EDITGENE provides a comprehensive suite of CRISPR services to enable such investigations with high precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for sodium-dependent multivitamin transmembrane transporter activity research.
Frequently Asked Questions About sodium-dependent multivitamin transmembrane transporter activity
What is GO:0008523?
GO:0008523 is the Gene Ontology term for sodium-dependent multivitamin transmembrane transporter activity, which moves pantothenate, biotin and lipoate across membranes using sodium.
What genes are involved in sodium-dependent multivitamin transmembrane transporter activity?
The primary gene is SLC5A6, which encodes the sodium-dependent multivitamin transporter (SMVT).
What vitamins are transported by SMVT?
SMVT transports pantothenate (vitamin B5), biotin (vitamin B7) and lipoate (lipoic acid).
How is sodium-dependent multivitamin transport studied?
Common methods include radiolabeled uptake assays, electrophysiology, and CRISPR-based genetic screens.
What diseases are linked to defective multivitamin transport?
Defects can contribute to vitamin deficiency disorders and metabolic conditions such as biotin-responsive disorders.
Is SMVT the same as SLC5A6?
Yes, SMVT is the protein product of the SLC5A6 gene.
What is the reaction catalyzed by GO:0008523?
The reaction is multivitamin(out) + Na+(out) = multivitamin(in) + Na+(in).
Can CRISPR be used to study SMVT function?
Yes, CRISPR knockout, point mutation, knock-in and overexpression models are powerful tools for studying SMVT.
What are the substrates of sodium-dependent multivitamin transporter?
Pantothenate, biotin and lipoate are the main substrates.
Why is sodium needed for multivitamin transport?
Sodium provides the driving force for secondary active transport of vitamins against their concentration gradient.
Conclusion
GO:0008523, sodium-dependent multivitamin transmembrane transporter activity, is a critical molecular function for cellular uptake of pantothenate, biotin and lipoate. Its study illuminates vitamin homeostasis, metabolic disease, and potential therapeutic targets. CRISPR-based models and EDITGENE services empower researchers to dissect this activity with precision.
References
- 1. Prasad PD et al.. 2000. Structure and function of mammalian sodium-dependent multivitamin transporter.. Curr Opin Clin Nutr Metab Care 3(4):263-6 PMID: 10929671
- 2. Prasad PD et al.. 1998. Cloning and functional expression of a cDNA encoding a mammalian sodium-dependent vitamin transporter mediating the uptake of pantothenate, biotin, and lipoate.. J Biol Chem 273(13):7501-6 PMID: 9516450
