TCTN1: A Ciliary Protein Essential for Hedgehog Signaling and Neural Development
Comprehensive genomic and clinical overview of TCTN1, a key component of the tectonic complex implicated in Joubert syndrome and related ciliopathies.
Gene Information Card
| Symbol | TCTN1 |
|---|---|
| Full Name | tectonic family member 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 12q24.11 |
| NCBI Gene ID | 79600 ncbi.nlm.nih.gov/gene/79600 |
| Ensembl ID | ENSG00000124813 |
| UniProt ID | Q2MV58 |
| OMIM ID | 609863 |
| HGNC ID | 25713 |
| Aliases | TECT1, C12orf38, MKS13, JBTS13 |
Description
TCTN1 encodes a member of the tectonic family, a group of proteins localized to the transition zone of primary cilia. TCTN1 is essential for ciliary gatekeeping and Hedgehog signal transduction. Mutations in TCTN1 disrupt ciliary function and are associated with Joubert syndrome (JBTS13) and Meckel-Gruber syndrome (MKS13), both severe ciliopathies characterized by brain malformations, renal cysts, and polydactyly.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Joubert syndrome 13 (JBTS13) | Loss-of-function mutations impair ciliary transition zone integrity, disrupting Hedgehog signaling and causing cerebellar vermis hypoplasia and molar tooth sign. | ClinVar, OMIM |
| Meckel-Gruber syndrome 13 (MKS13) | Biallelic null mutations lead to severe ciliary dysfunction, resulting in encephalocele, polycystic kidneys, and polydactyly. | ClinVar, OMIM |
| Orofaciodigital syndrome (OFD) | Rare variants may contribute to ciliary defects affecting craniofacial development. | ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.3 | Medium |
| Cerebellum | 8.7 | Low |
| Kidney | 6.5 | Low |
| Lung | 5.2 | Low |
| Heart | 4.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 9.8 | Embryonic kidney cells; moderate expression |
| SH-SY5Y | 7.3 | Neuroblastoma cells; relevant for neural cilia studies |
| HeLa | 6.1 | Cervical carcinoma; low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1234C>T (p.Arg412*) | Nonsense | <0.01% | Loss of function; truncation of protein; associated with Joubert syndrome |
| c.789_790del (p.Glu264fs) | Frameshift | <0.01% | Loss of function; premature stop; linked to Meckel-Gruber syndrome |
| c.1556G>A (p.Arg519Gln) | Missense | <0.01% | Likely damaging; disrupts ciliary localization |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations that truncate the protein or cause nonsense-mediated decay, leading to ciliary dysfunction and ciliopathy phenotypes.
Gain of Function (GOF)
No gain-of-function mutations reported for TCTN1.
Dominant Negative (DN)
No dominant-negative mutations reported; disease inheritance is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • ciliary transition zone (GO:0035869) | • protein binding (GO:0005515) |
| • cilium assembly (GO:0060271) | • hedgehog signaling pathway (GO:0007224) |
| • cell projection organization (GO:0030030) |
Pathways
• Hedgehog signaling pathway (Reactome R-HSA-5358351)
• Cilium assembly (Reactome R-HSA-5620912)
• Tectonic complex (Reactome R-HSA-5620920)
Protein Summary
TCTN1 is a 609-amino-acid protein containing a coiled-coil domain and a transmembrane domain. It localizes to the ciliary transition zone as part of the tectonic complex, which regulates protein entry and exit from the cilium. TCTN1 is critical for Hedgehog signal transduction; its loss disrupts Gli transcription factor processing and leads to developmental defects.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TCTN1 Knockout HEK293 Cell Line | EDJ-KQ15670 | Human | 79600 | Details Get a Quote |
| TCTN1 Knockout HeLa Cell Line | EDJ-KQ45341 | Human | 79600 | Details Get a Quote |
| TCTN1 Knockout A-549 Cell Line | EDJ-KQ46570 | Human | 79600 | Details Get a Quote |
| TCTN1 Knockout HCT 116 Cell Line | EDJ-KQ46571 | Human | 79600 | Details Get a Quote |
