CLXN Gene - Calaxin
Essential regulator of ciliary motility and dynein arm assembly
Gene Information Card
| Symbol | CLXN |
|---|---|
| Full Name | calaxin |
| Gene Type | protein-coding |
| Chromosomal Location | 8q21.11 |
| NCBI Gene ID | 644997 ncbi.nlm.nih.gov/gene/644997 |
| Ensembl ID | ENSG00000177917 |
| UniProt ID | Q8N4C8 |
| OMIM ID | 616399 |
| HGNC ID | 33618 |
| Aliases | FLJ38717, MGC16121, dJ222E13.1 |
Description
The CLXN gene encodes calaxin, a calcium-binding protein that regulates dynein arm activity in cilia and flagella. Calaxin is essential for proper ciliary motility, particularly in the respiratory tract and sperm flagella. Mutations in CLXN cause primary ciliary dyskinesia (PCD) with situs inversus (Kartagener syndrome) due to defective axonemal dynein regulation.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Primary ciliary dyskinesia 44 | Loss-of-function mutations in CLXN disrupt calaxin-mediated regulation of outer dynein arms, impairing ciliary beat frequency and waveform. | OMIM: 618781; ClinVar; PubMed: 31611251 |
| Kartagener syndrome | Biallelic CLXN mutations lead to situs inversus totalis and chronic respiratory symptoms due to defective mucociliary clearance. | OMIM: 244400; ClinVar; PubMed: 31611251 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Lung | 8.3 | Low |
| Fallopian tube | 7.1 | Low |
| Trachea | 6.9 | Low |
| Brain | 1.2 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| BEAS-2B (bronchial epithelial) | 5.4 | Low expression |
| HepG2 (liver) | 0.8 | Not detected |
| K562 (leukemia) | 0.5 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | missense | Rare | Loss of start codon, likely loss of function |
| c.325C>T (p.Arg109*) | nonsense | Rare | Premature stop, loss of function |
| c.494_495del (p.Glu165Glyfs*12) | frameshift | Rare | Frameshift, loss of function |
Mutation functional classification
Loss of Function (LOF)
Biallelic loss-of-function mutations in CLXN cause primary ciliary dyskinesia with situs inversus.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported.
View complete mutation data：
Gene Ontology (GO)
| • calcium ion binding (GO:0005509) | • cytoplasm (GO:0005737) |
| • cytoskeleton (GO:0005856) | • cilium (GO:0005929) |
| • axoneme assembly (GO:0035082) | • cilium-dependent cell motility (GO:0060285) |
Pathways
• Cilium assembly and regulation (Reactome: R-HSA-5617833)
• Axonemal dynein complex assembly (Reactome: R-HSA-5620912)
Protein Summary
Calaxin is a 22 kDa calcium-binding protein localized to the axoneme of cilia and flagella. It interacts with the outer dynein arm to regulate microtubule sliding in response to calcium signals. Loss of calaxin leads to reduced ciliary beat frequency and impaired mucociliary clearance, resulting in primary ciliary dyskinesia.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CLXN Knockout HEK293 Cell Line | EDJ-KQ12955 | Human | 79645 | Details Get a Quote |
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