GO:0015111 iodide transmembrane transporter activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0015111 iodide transmembrane transporter activity is a molecular function that enables the transfer of iodide ions (I-) across biological membranes.
• The major protein mediating this activity in thyroid and other tissues is the sodium/iodide symporter (NIS, encoded by SLC5A5), which couples iodide transport to the sodium gradient.
• Iodide transport is essential for thyroid hormone synthesis, and its dysregulation is linked to thyroid cancer, autoimmune thyroid disease, and congenital hypothyroidism.
• CFTR (ABCC7) can also transport iodide, and this activity is exploited in live-cell imaging assays to evaluate CFTR function and rescue by modulators.
• Experimental models for studying iodide transport include knockout and point-mutation cell lines, overexpression systems, and CRISPR library screening.
• EDITGENE provides CRISPR services to generate knockout, point-mutation, knock-in, and overexpression cell models for iodide transporter research.
Description
Iodide transmembrane transporter activity (GO:0015111) is a molecular function that enables the movement of iodide ions across cell membranes. This activity is fundamental to thyroid physiology, as it allows the thyroid gland to concentrate iodide for the synthesis of thyroid hormones, which regulate metabolism, growth, and development. Beyond the thyroid, iodide transporters are expressed in other tissues such as salivary glands, gastric mucosa, and mammary glands, where they contribute to iodide secretion and potentially to host defense. In recent years, iodide transport has gained attention in cancer research because it can be exploited for diagnostic imaging and targeted radiotherapy. Additionally, the cystic fibrosis transmembrane conductance regulator (CFTR) exhibits iodide transport activity, and this property has been used to develop sensitive assays for CFTR function and modulator testing. Understanding the molecular mechanisms, regulation, and disease relevance of iodide transporters is therefore critical for both basic biology and clinical applications.
iodide transmembrane transporter activity At A Glance
| GO ID | GO:0015111 |
|---|---|
| GO term | iodide transmembrane transporter activity |
| Ontology | molecular_function |
| Synonym | none |
| Major function | Transfer of iodide ions across membranes |
| Major protein | SLC5A5 (NIS), CFTR, others |
| Associated diseases | Thyroid cancer, congenital hypothyroidism, cystic fibrosis |
| Research methods | Live-cell imaging, electrophysiology, radiotracer uptake, CRISPR screens |
What Is GO:0015111?
According to the Gene Ontology, iodide transmembrane transporter activity (GO:0015111) is defined as the function that enables the transfer of iodide ions from one side of a membrane to the other. This activity is typically mediated by integral membrane proteins that form channels or carriers, allowing iodide to cross lipid bilayers down its electrochemical gradient or through coupled transport mechanisms.
Why Is iodide transmembrane transporter activity Important in Cell Biology?
Iodide transmembrane transporter activity is essential for thyroid hormone biosynthesis and systemic iodide homeostasis. Defects in iodide transport cause congenital hypothyroidism and are associated with thyroid cancer and autoimmune thyroid disease. Moreover, iodide transport activity in CFTR is used as a readout for CFTR function, aiding in the development of therapies for cystic fibrosis. Thus, studying this activity provides insights into endocrine physiology, cancer biology, and genetic disorders.
• Essential for thyroid hormone production and metabolic regulation.
• Dysregulation leads to thyroid cancer and congenital hypothyroidism.
• Enables non-invasive imaging of thyroid and other tissues using radioactive iodide.
• CFTR iodide transport serves as a biomarker for cystic fibrosis modulator efficacy.
• Provides a target for cancer therapy via radioactive iodide ablation.
• Involved in iodide secretion in salivary glands, gastric mucosa, and mammary glands.
• Facilitates high-throughput screening for compounds that modulate iodide transport.
• Offers a model system to study membrane transport mechanisms and ion selectivity.
What Happens During iodide transmembrane transporter activity?
Iodide uptake at the basolateral membrane
In simple terms: Iodide is taken up from the blood into the cell.
In thyroid follicular cells, the sodium/iodide symporter (NIS) located on the basolateral membrane couples the inward transport of iodide to the sodium gradient, concentrating iodide up to 20-40 times above plasma levels.
Intracellular iodide transport and efflux
In simple terms: Iodide moves inside the cell and is then released into the follicle.
After uptake, iodide diffuses to the apical membrane, where it is transported into the follicular lumen by pendrin (SLC26A4) and possibly other transporters, a step required for thyroid hormone synthesis.
Iodide transport in non-thyroid tissues
In simple terms: Other tissues also move iodide for various purposes.
NIS is expressed in salivary glands, gastric mucosa, and lactating mammary glands, where it mediates iodide secretion into saliva, gastric juice, and milk, respectively. CFTR can also transport iodide in epithelial cells, and this activity is used to assess CFTR function.
Regulation of iodide transport
In simple terms: The process is controlled by hormones and cellular signals.
Thyroid-stimulating hormone (TSH) regulates NIS expression and localization, thereby controlling iodide uptake. In CFTR, iodide transport is regulated by phosphorylation and nucleotide binding, and is influenced by CFTR modulators.
Key Genes Involved in GO:0015111 iodide transmembrane transporter activity
The following genes encode proteins that mediate or regulate iodide transmembrane transporter activity, as supported by published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SLC5A5 | Sodium/iodide symporter (NIS) that mediates active iodide uptake | Knockout models to study thyroid function and cancer |
| SLC26A4 | Pendrin, an anion exchanger that transports iodide at the apical membrane | Point mutations linked to Pendred syndrome and thyroid dyshormonogenesis |
| CFTR | Chloride and iodide channel; can transport iodide | Used as a reporter for CFTR function and modulator testing |
| TSHR | Thyroid-stimulating hormone receptor that regulates NIS expression | Knockout and overexpression models for thyroid disease |
| PAX8 | Transcription factor regulating thyroid-specific genes including SLC5A5 | Knockout models to study thyroid development |
| NKX2-1 | Transcription factor essential for thyroid and lung development | Knockout models for congenital hypothyroidism |
| FOXE1 | Transcription factor involved in thyroid morphogenesis | Point mutations associated with thyroid dysgenesis |
| SLC26A7 | Anion transporter expressed in thyroid and kidney | Potential role in iodide transport |
| ANO1 | Calcium-activated chloride channel that can permeate iodide | Overexpression models to study anion transport |
| CLCN5 | Chloride/proton exchanger with iodide transport capacity | Knockout models for kidney and thyroid function |
| SLC12A2 | Sodium-potassium-chloride cotransporter that may influence iodide transport | Knockout models for epithelial transport |
| ATP1A1 | Na+/K+-ATPase that maintains sodium gradient for NIS | Point mutation models to study ion gradients |
| KCNQ1 | Potassium channel that facilitates apical iodide efflux | Knockout models for thyroid dysfunction |
| SLC4A4 | Sodium bicarbonate cotransporter that may affect iodide transport | Knockout models for acid-base balance |
| SLC22A4 | Organic cation transporter with potential iodide transport | Overexpression for transport studies |
| SLC16A10 | Aromatic amino acid transporter that may transport iodide | Knockout models for thyroid hormone metabolism |
| SLC7A5 | L-type amino acid transporter that can transport iodide | Overexpression models for cancer research |
| SLC3A2 | Heavy chain of amino acid transporters, may influence iodide uptake | Knockout models for transporter function |
How Is iodide transmembrane transporter activity Regulated?
Iodide transmembrane transporter activity is primarily regulated by thyroid-stimulating hormone (TSH), which controls the expression and membrane localization of the sodium/iodide symporter (NIS) in thyroid cells. Additionally, iodide itself can autoregulate its transport through the Wolff-Chaikoff effect, reducing NIS expression and iodide uptake. In CFTR, iodide transport is regulated by phosphorylation and ATP binding, and can be modulated by pharmacological correctors and potentiators.
iodide transmembrane transporter activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC5A5 | Congenital hypothyroidism, thyroid cancer | Knockout and point-mutation cell lines |
| SLC26A4 | Pendred syndrome, thyroid dyshormonogenesis | Knock-in of patient mutations |
| CFTR | Cystic fibrosis | Overexpression of F508del and modulator testing |
| TSHR | Graves' disease, congenital hypothyroidism | Knockout and overexpression models |
| PAX8 | Thyroid dysgenesis | Knockout models |
Thyroid cancer
Loss of iodide transport activity, often due to decreased NIS expression or mislocalization, leads to radioiodide-refractory thyroid cancer, which is associated with poor prognosis. Mutations in genes such as BRAF and RAS can downregulate NIS, contributing to dedifferentiation.
Congenital hypothyroidism
Mutations in SLC5A5, SLC26A4, TSHR, PAX8, NKX2-1, and FOXE1 cause congenital hypothyroidism due to defective iodide transport or thyroid dysgenesis. These defects impair thyroid hormone synthesis, leading to developmental delays if untreated.
Cystic fibrosis
CFTR mutations, such as F508del, reduce iodide transport activity, which can be measured using iodide-sensitive indicators. This assay is used to evaluate the efficacy of CFTR modulators like lumacaftor and ivacaftor.
Autoimmune thyroid disease
In Graves' disease and Hashimoto's thyroiditis, autoantibodies against TSHR or NIS can alter iodide transport, leading to hyper- or hypothyroidism.
From iodide transmembrane transporter activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of SLC5A5 affect iodide uptake? | SLC5A5 knockout cell line |
| How do patient mutations in SLC26A4 affect iodide transport? | Point-mutation knock-in cell line |
| Can CFTR modulators rescue iodide transport in F508del cells? | CFTR F508del overexpression and iodide imaging |
| What is the role of TSHR in regulating NIS expression? | TSHR knockout and overexpression models |
| Can CRISPR screening identify novel regulators of iodide transport? | Genome-wide CRISPR knockout library |
| How does iodide transport affect thyroid cancer cell proliferation? | Overexpression of NIS in cancer cell lines |
How to Study the iodide transmembrane transporter activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Iodide-sensitive fluorescent indicator | Intracellular iodide concentration changes | Live-cell imaging of CFTR activity |
| Radioactive iodide uptake | Active iodide transport | Thyroid cell function and NIS activity |
| Patch-clamp | Ion currents | CFTR channel function and modulator testing |
| Ussing chamber | Transepithelial ion transport | Epithelial iodide secretion |
| CRISPR knockout screen | Gene essentiality for iodide transport | Discovery of novel regulators |
| RNA-seq | Gene expression changes | Transcriptional regulation of transporters |
| Proteomics | Protein abundance and interactions | Identification of transporter complexes |
| Immunofluorescence | Protein localization | Membrane targeting of NIS or CFTR |
Live-cell imaging with iodide-sensitive indicators
Selective iodide indicators enable real-time monitoring of iodide transport activity in live cells, as demonstrated for CFTR function evaluation.
Radiotracer uptake assays
Radioactive iodide (e.g., I-125 or I-131) uptake assays are standard for measuring NIS-mediated transport in thyroid cells and other tissues.
Electrophysiology
Patch-clamp and Ussing chamber techniques can measure iodide currents through channels such as CFTR, providing direct functional data.
CRISPR screening
Genome-wide CRISPR knockout screens can identify genes that regulate iodide transport, using iodide-sensitive reporters or survival in radioactive iodide.
How CRISPR Can Be Used to Study GO:0015111 iodide transmembrane transporter activity
Knockout
CRISPR knockout of SLC5A5 or CFTR eliminates iodide transport activity, providing a clean background to study transporter function and to validate specificity of iodide indicators.
Point Mutation
Introducing patient-specific point mutations (e.g., F508del in CFTR or mutations in SLC26A4) allows assessment of their impact on iodide transport and response to therapeutics.
Knock-in
Knock-in of reporter tags or disease-associated variants enables tracking of transporter localization and function in physiologically relevant contexts.
Overexpression
Overexpression of NIS or CFTR in heterologous systems facilitates biochemical and pharmacological studies of iodide transport, including high-throughput screening.
How EDITGENE Supports iodide transmembrane transporter activity Research
Researchers studying iodide transmembrane transporter activity-related genes often need to determine whether a candidate gene is causally involved in iodide transport, how mutations affect function, and whether therapeutic interventions can restore activity. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for iodide transmembrane transporter activity research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MFSD8 Knockout HEK293T Cell Line | EDJ-KQ166 | Human | 256471 | Details Get a Quote |
| SLC26A4 Knockout HEK293 Cell Line | EDJ-KQ2080 | Human | 5172 | Details Get a Quote |
| ANO1 Knockout HEK293 Cell Line | EDJ-KQ2881 | Human | 55107 | Details Get a Quote |
| SLC5A5 Knockout HEK293 Cell Line | EDJ-KQ5768 | Human | 6528 | Details Get a Quote |
| SLC5A6 Knockout HEK293 Cell Line | EDC08388 | Human | 8884 | Details Get a Quote |
| MFSD8 Knockout HEK293 Cell Line | EDJ-KQ14252 | Human | 256471 | Details Get a Quote |
| MFSD8 Knockout A-549 Cell Line | EDJ-KQ44249 | Human | 256471 | Details Get a Quote |
| MFSD8 Knockout HCT 116 Cell Line | EDJ-KQ44250 | Human | 256471 | Details Get a Quote |
| MFSD8 Knockout HeLa Cell Line | EDJ-KQ44251 | Human | 256471 | Details Get a Quote |
| ANO1 Knockout A-549 Cell Line | EDJ-KQ25313 | Human | 55107 | Details Get a Quote |
| ANO1 Knockout HCT 116 Cell Line | EDJ-KQ25315 | Human | 55107 | Details Get a Quote |
| SLC5A6 Knockout A-549 Cell Line | EDJ-KQ30406 | Human | 8884 | Details Get a Quote |
| SLC5A6 Knockout HCT 116 Cell Line | EDC07824 | Human | 8884 | Details Get a Quote |
| SLC5A6 Knockout HeLa Cell Line | EDJ-KQ30408 | Human | 8884 | Details Get a Quote |
| SLC26A4 Knockout HeLa Cell Line | EDJ-KQ54113 | Human | 5172 | Details Get a Quote |
Displaying Records 1 To 15 Of 25 Records
Frequently Asked Questions About iodide transmembrane transporter activity
What is iodide transmembrane transporter activity?
It is a molecular function (GO:0015111) that enables the transfer of iodide ions across membranes, essential for thyroid hormone synthesis and other processes.
What genes are involved in iodide transmembrane transporter activity?
Key genes include SLC5A5 (NIS), SLC26A4 (pendrin), and CFTR, among others.
How is iodide transport measured in the lab?
Common methods include radioactive iodide uptake, live-cell imaging with iodide-sensitive indicators, and electrophysiology.
What diseases are associated with defective iodide transport?
Congenital hypothyroidism, thyroid cancer, Pendred syndrome, and cystic fibrosis.
Can CRISPR be used to study iodide transporters?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to dissect transporter function.
What is the role of CFTR in iodide transport?
CFTR can transport iodide, and this activity is used as a readout for CFTR function and modulator efficacy in cystic fibrosis research.
How does TSH regulate iodide transport?
TSH stimulates the expression and membrane localization of NIS, thereby increasing iodide uptake in thyroid cells.
What is the Wolff-Chaikoff effect?
It is an autoregulatory mechanism where high iodide levels transiently inhibit iodide transport and thyroid hormone synthesis.
Are there animal models for iodide transport disorders?
Yes, knockout mice for Slc5a5, Slc26a4, and Cftr have been generated to study thyroid and epithelial transport defects.
What services does EDITGENE offer for iodide transporter research?
EDITGENE provides CRISPR knockout, point mutation, knock-in, overexpression cell models, library screening, and bioinformatics analysis.
Conclusion
Iodide transmembrane transporter activity (GO:0015111) is a critical molecular function with profound implications for thyroid physiology, epithelial transport, and human disease. The sodium/iodide symporter (NIS) and CFTR are prominent mediators, and their dysfunction underlies congenital hypothyroidism, thyroid cancer, and cystic fibrosis. Advances in live-cell imaging and CRISPR-based models are accelerating our understanding of iodide transport and enabling the development of targeted therapies. Continued research into the regulation and pharmacology of iodide transporters holds promise for improving diagnosis and treatment of related disorders.
References
- 4. De la Vieja A et al.. 2018. Role of iodide metabolism in physiology and cancer.. Endocr Relat Cancer 25(4):R225-R245 PMID: 29437784
- 8. Morse J et al.. 2025. Development of a selective-iodide indicator for live-cell imaging and evaluation of CFTR activity.. Sens Diagn 4(10):833-838 PMID: 40895092
