TCTN2: A Ciliary Protein Critical for Hedgehog Signaling and Associated with Joubert Syndrome
Comprehensive genomic and functional analysis of TCTN2, a key component of the tectonic complex involved in ciliopathies.
Gene Information Card
| Symbol | TCTN2 |
|---|---|
| Full Name | tectonic family member 2 |
| Gene Type | protein-coding |
| Chromosomal Location | 12q24.31 |
| NCBI Gene ID | 79867 ncbi.nlm.nih.gov/gene/79867 |
| Ensembl ID | ENSG00000168778 |
| UniProt ID | Q96GX1 |
| OMIM ID | 613846 |
| HGNC ID | 25774 |
| Aliases | C12orf2, JBTS24, MKS8, TECT2 |
Description
TCTN2 (tectonic family member 2) encodes a protein that is a component of the tectonic complex, which is essential for ciliary membrane biogenesis and hedgehog signaling. Mutations in TCTN2 cause Joubert syndrome 24 (JBTS24) and Meckel syndrome 8 (MKS8), both severe ciliopathies characterized by developmental defects and organ malformations.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Joubert syndrome 24 (JBTS24) | Loss-of-function mutations disrupt ciliary function and hedgehog signaling, leading to cerebellar vermis hypoplasia, intellectual disability, and retinal dystrophy. | ClinVar, OMIM |
| Meckel syndrome 8 (MKS8) | Biallelic null mutations impair ciliogenesis, causing encephalocele, polycystic kidneys, and polydactyly. | ClinVar, OMIM |
| Ciliopathy-related phenotypes | Heterozygous variants may contribute to milder ciliary dysfunction, though penetrance is variable. | ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.8 | Medium |
| Brain (cerebellum) | 8.5 | Medium |
| Kidney | 7.2 | Medium |
| Lung | 5.1 | Low |
| Liver | 2.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 9.4 | Embryonic kidney cells; high expression |
| HeLa | 6.7 | Cervical cancer cells; moderate expression |
| HepG2 | 4.1 | Hepatocellular carcinoma; low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1196G>A (p.Trp399*) | Nonsense | <0.01% | Loss of function; truncation of protein |
| c.1462C>T (p.Arg488*) | Nonsense | <0.01% | Loss of function; premature stop codon |
| c.1A>G (p.Met1?) | Start loss | <0.01% | Loss of function; no translation initiation |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations leading to truncated or absent protein; associated with Joubert and Meckel syndromes.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Not reported.
View complete mutation data：
Gene Ontology (GO)
| • cilium assembly | • ciliary membrane |
| • hedgehog signaling pathway | • protein localization to cilium |
| • cell projection organization |
Pathways
• Hedgehog signaling pathway (Reactome R-HSA-5358351)
• Cilium assembly (Reactome R-HSA-5620920)
Protein Summary
TCTN2 is a 707-amino acid protein with a transmembrane domain and a coiled-coil region. It localizes to the transition zone of primary cilia and interacts with other tectonic complex members (TCTN1, TCTN3) to regulate ciliary gate integrity and hedgehog signal transduction.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TCTN2 Knockout HEK293 Cell Line | EDJ-KQ15671 | Human | 79867 | Details Get a Quote |
| TCTN2 Knockout A-549 Cell Line | EDJ-KQ46573 | Human | 79867 | Details Get a Quote |
| TCTN2 Knockout HCT 116 Cell Line | EDJ-KQ46574 | Human | 79867 | Details Get a Quote |
| TCTN2 Knockout HeLa Cell Line | EDJ-KQ46575 | Human | 79867 | Details Get a Quote |
