SPAG1: Sperm Associated Antigen 1
A dynein axonemal assembly factor implicated in primary ciliary dyskinesia and male infertility
Gene Information Card
| Symbol | SPAG1 |
|---|---|
| Full Name | Sperm Associated Antigen 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 8q22.3 |
| NCBI Gene ID | 6674 ncbi.nlm.nih.gov/gene/6674 |
| Ensembl ID | ENSG00000104490 |
| UniProt ID | Q07617 |
| OMIM ID | 603395 |
| HGNC ID | 11212 |
| Aliases | CT79, DNAAF18, HEL-S-70p, TPIS, hSMP-1 |
Description
SPAG1 encodes a protein involved in the assembly of dynein arms in cilia and flagella. It functions as a dynein axonemal assembly factor (DNAAF18), essential for proper ciliary motility. Mutations in SPAG1 cause primary ciliary dyskinesia (PCD) with situs inversus and male infertility due to defective sperm flagella.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Primary ciliary dyskinesia (PCD) | Loss-of-function mutations impair dynein arm assembly, leading to defective ciliary motility | ClinVar, OMIM |
| Male infertility (asthenozoospermia) | Defective flagellar dynein assembly causes sperm immotility | OMIM, PubMed |
| Situs inversus | Disrupted nodal cilia function during embryogenesis leads to randomized left-right asymmetry | OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 28.5 | High |
| Fallopian tube | 12.3 | Medium |
| Lung | 8.1 | Medium |
| Trachea | 6.7 | Medium |
| Brain | 0.5 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Sperm cells | N/A | High expression in flagella |
| Bronchial epithelial cells | N/A | Expressed in ciliated cells |
| hTERT-RPE1 | N/A | Ciliated cell model |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1393C>T (p.Arg465*) | Nonsense | Rare | Loss of function |
| c.2026C>T (p.Arg676*) | Nonsense | Rare | Loss of function |
| c.1045C>T (p.Arg349*) | Nonsense | Rare | Loss of function |
| c.2272C>T (p.Arg758*) | Nonsense | Rare | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations cause premature termination, leading to absent or non-functional protein, resulting in defective dynein arm assembly.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported; inheritance is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Ciliary motility (dynein arm assembly)
• Spermatogenesis (flagellar assembly)
Protein Summary
SPAG1 is a 1002-amino acid protein localized to the cytoplasm and cilia. It acts as a dynein axonemal assembly factor, facilitating the preassembly of dynein complexes in the cytoplasm before transport to cilia and flagella. The protein contains coiled-coil domains and is essential for proper ciliary beat frequency and sperm motility.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SPAG17 Knockout HEK293 Cell Line | EDC08184 | Human | 200162 | Details Get a Quote |
| SPAG1 Knockout HEK293 Cell Line | EDJ-KQ15425 | Human | 6674 | Details Get a Quote |
| SPAG11A Knockout HEK293 Cell Line | EDJ-KQ15427 | Human | 653423 | Details Get a Quote |
| SPAG16 Knockout HEK293 Cell Line | EDJ-KQ15428 | Human | 79582 | Details Get a Quote |
| SPAG1 Knockout HCT 116 Cell Line | EDJ-KQ46209 | Human | 6674 | Details Get a Quote |
| SPAG1 Knockout HeLa Cell Line | EDJ-KQ46210 | Human | 6674 | Details Get a Quote |
| SPAG16 Knockout A-549 Cell Line | EDJ-KQ46213 | Human | 79582 | Details Get a Quote |
| SPAG1 Knockout A-549 Cell Line | EDJ-KQ47101 | Human | 6674 | Details Get a Quote |
| SPAG16 Knockout HeLa Cell Line | EDJ-KQ47107 | Human | 79582 | Details Get a Quote |
| SPAG11B Knockout HEK293 Cell Line | EDJ-KQ50965 | Human | 10407 | Details Get a Quote |
| SPAG11B Knockout HeLa Cell Line | EDJ-KQ55402 | Human | 10407 | Details Get a Quote |
| SPAG17 Knockout HeLa Cell Line | EDJ-KQ59000 | Human | 200162 | Details Get a Quote |
| SPAG11A Knockout HeLa Cell Line | EDJ-KQ60644 | Human | 653423 | Details Get a Quote |
| SPAG11B Knockout A-549 Cell Line | EDJ-KQ63881 | Human | 10407 | Details Get a Quote |
| SPAG17 Knockout A-549 Cell Line | EDJ-KQ67484 | Human | 200162 | Details Get a Quote |
