SPAG6 Gene: Sperm Associated Antigen 6
Key regulator of ciliary motility and sperm flagellar function
Gene Information Card
| Symbol | SPAG6 |
|---|---|
| Full Name | Sperm Associated Antigen 6 |
| Gene Type | Protein coding |
| Chromosomal Location | 10p12.2 |
| NCBI Gene ID | 9576 ncbi.nlm.nih.gov/gene/9576 |
| Ensembl ID | ENSG00000177370 |
| UniProt ID | O75602 |
| OMIM ID | 605730 |
| HGNC ID | 11212 |
| Aliases | PF16, CTL4, hPF16, MGC126562 |
Description
SPAG6 (Sperm Associated Antigen 6) encodes a protein that is a component of the axoneme central apparatus, essential for ciliary and flagellar motility. The protein localizes to the central pair of microtubules in cilia and flagella, where it regulates dynein-driven microtubule sliding. SPAG6 is highly expressed in testis and tissues with motile cilia, such as respiratory epithelium. Mutations in SPAG6 are associated with primary ciliary dyskinesia and male infertility due to sperm flagellar defects.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Primary ciliary dyskinesia (PCD) | Loss-of-function mutations disrupt axonemal central pair structure, impairing ciliary beat frequency and mucociliary clearance. | ClinVar, OMIM |
| Male infertility (asthenozoospermia) | Defects in SPAG6 cause sperm flagellar abnormalities, leading to reduced motility. | NCBI Gene, OMIM |
| Recurrent respiratory infections | Impaired mucociliary clearance due to ciliary dysfunction predisposes to chronic lung infections. | ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 48.2 | High |
| Fallopian tube | 12.5 | Medium |
| Lung | 8.1 | Medium |
| Brain | 2.3 | Low |
| Heart | 1.5 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| hTERT-RPE1 | 15.4 | Retinal pigment epithelial cells with motile cilia |
| BEAS-2B | 10.2 | Bronchial epithelial cells |
| HeLa | 0.8 | Cervical carcinoma, low expression |
| HEK293 | 1.2 | Embryonic kidney, low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.295C>T (p.Arg99*) | Nonsense | Rare | Premature stop codon; loss of protein function |
| c.434_435delAG (p.Glu145Valfs*2) | Frameshift | Rare | Truncated protein; loss of axonemal localization |
| c.788G>A (p.Arg263His) | Missense | Unknown | Potential disruption of central pair binding |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations (e.g., p.Arg99*, p.Glu145Valfs*2) cause complete loss of SPAG6 protein, leading to ciliary and flagellar immotility.
Gain of Function (GOF)
No gain-of-function mutations reported for SPAG6.
Dominant Negative (DN)
No dominant-negative mutations reported; SPAG6-associated diseases are typically recessive.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Ciliary motility (Reactome: R-HSA-5620920)
• Axoneme assembly (Reactome: R-HSA-5620912)
Protein Summary
SPAG6 is a 509-amino acid protein (UniProt O75602) that contains multiple armadillo-type repeats and localizes to the central pair of microtubules in cilia and flagella. It interacts with other axonemal proteins such as SPAG16 and SPAG17 to stabilize the central apparatus. The protein is essential for the regulation of ciliary beat frequency and sperm flagellar waveform. Loss of SPAG6 leads to disorganized axonemal structure and impaired motility.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SPAG6 Knockout HEK293 Cell Line | EDJ-KQ6643 | Human | 9576 | Details Get a Quote |
| SPAG6 Knockout HeLa Cell Line | EDJ-KQ55200 | Human | 9576 | Details Get a Quote |
| SPAG6 Knockout A-549 Cell Line | EDJ-KQ63682 | Human | 9576 | Details Get a Quote |
| SPAG6 Knockout HCT 116 Cell Line | EDJ-KQ72144 | Human | 9576 | Details Get a Quote |
