TPO Gene - Thyroid Peroxidase
Key enzyme in thyroid hormone synthesis and biomarker for autoimmune thyroid disease
Gene Information Card
| Symbol | TPO |
|---|---|
| Full Name | Thyroid Peroxidase |
| Gene Type | protein-coding |
| Chromosomal Location | 2p25.3 |
| NCBI Gene ID | 7173 ncbi.nlm.nih.gov/gene/7173 |
| Ensembl ID | ENSG00000115705 |
| UniProt ID | P07202 |
| OMIM ID | 274500 |
| HGNC ID | 12015 |
| Aliases | TPX, MSA, TPO1 |
Description
The TPO gene encodes thyroid peroxidase, a membrane-bound glycoprotein localized to the apical membrane of thyroid follicular cells. This enzyme catalyzes the iodination of tyrosine residues in thyroglobulin and the coupling of iodotyrosines to form thyroid hormones T3 and T4. TPO is a major autoantigen in autoimmune thyroid diseases, and mutations in TPO cause congenital hypothyroidism due to a total iodide organification defect.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Congenital hypothyroidism due to thyroid dyshormonogenesis type 2A | Loss-of-function mutations impair iodide organification, reducing thyroid hormone synthesis | OMIM #274500; ClinVar pathogenic variants |
| Hashimoto thyroiditis | Autoantibodies against TPO target thyroid tissue, leading to chronic inflammation and hypothyroidism | ClinVar; NCBI GeneReviews |
| Graves disease | TPO autoantibodies present in subset of patients; associated with thyroid autoimmunity | NCBI Gene; literature |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Thyroid | 189.2 | High |
| Salivary gland | 0.3 | Not detected |
| Adrenal gland | 0.1 | Not detected |
| Liver | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Thyroid follicular epithelial cells | 189.2 | Primary site of expression |
| Nthy-ori 3-1 (thyroid cell line) | High | Model for TPO expression studies |
| HeLa | 0.0 | No detectable expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.2268dupT (p.Glu757*) | Frameshift / nonsense | Rare | Loss of function; congenital hypothyroidism |
| c.1198G>A (p.Gly400Ser) | Missense | Common in East Asian populations | Reduced enzymatic activity; associated with mild hypothyroidism |
| c.875C>T (p.Thr292Ile) | Missense | Rare | Impaired heme binding; loss of function |
Mutation functional classification
Loss of Function (LOF)
Most TPO mutations are loss-of-function, leading to defective iodide organification and congenital hypothyroidism.
Gain of Function (GOF)
No gain-of-function mutations reported in TPO.
Dominant Negative (DN)
Rare; some missense variants may exert dominant-negative effects in heterozygous state, but evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • peroxidase activity (GO:0004601) | • iron ion binding (GO:0005506) |
| • oxidoreductase activity (GO:0016491) | • iodide peroxidase activity (GO:0001570) |
| • plasma membrane (GO:0005886) | • integral component of membrane (GO:0016021) |
| • thyroid hormone generation (GO:0006590) |
Pathways
• Thyroid hormone synthesis (Reactome: R-HSA-209968)
• Iodine metabolism (KEGG: hsa04918)
Protein Summary
Thyroid peroxidase (TPO) is a 933-amino acid transmembrane glycoprotein with a large extracellular domain containing a heme-binding peroxidase active site. It catalyzes the oxidation of iodide to iodine and the subsequent iodination of thyroglobulin tyrosine residues, essential for thyroid hormone biosynthesis. TPO is the primary autoantigen in Hashimoto thyroiditis, and its measurement via anti-TPO antibodies is a key diagnostic test for autoimmune thyroid disease.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TPO Knockout HEK293 Cell Line | EDJ-KQ2905 | Human | 7173 | Details Get a Quote |
| TPO Knockout HeLa Cell Line | EDJ-KQ54687 | Human | 7173 | Details Get a Quote |
| TPO Knockout A-549 Cell Line | EDJ-KQ63172 | Human | 7173 | Details Get a Quote |
| TPO Knockout HCT 116 Cell Line | EDJ-KQ71643 | Human | 7173 | Details Get a Quote |
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