SPANXA2: Sperm Protein Associated with the Nucleus on the X Chromosome A2
A testis-specific gene encoding a sperm nuclear protein involved in spermatogenesis and male fertility.
Gene Information Card
| Symbol | SPANXA2 |
|---|---|
| Full Name | Sperm Protein Associated with the Nucleus on the X Chromosome A2 |
| Gene Type | Protein coding |
| Chromosomal Location | Xq27.1 |
| NCBI Gene ID | 728712 ncbi.nlm.nih.gov/gene/728712 |
| Ensembl ID | ENSG00000221923 |
| UniProt ID | Q9NS26 |
| OMIM ID | 300662 |
| HGNC ID | 30673 |
| Aliases | SPANX-A2, SPANXA, SPANX-A |
Description
SPANXA2 is a member of the SPANX (sperm protein associated with the nucleus on the X chromosome) gene family, which is expressed exclusively in the testis. The encoded protein is localized to the sperm nucleus and is thought to play a role in spermatogenesis, particularly in the post-meiotic stages of sperm maturation. SPANXA2 may also be involved in sperm–egg interaction and fertilization. Due to its testis-restricted expression, it has been studied as a potential cancer/testis antigen in certain malignancies.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Male infertility | Altered expression or mutation may impair spermatogenesis | Limited; expression studies in infertile men show reduced SPANXA2 mRNA levels (PMID: 19403107) |
| Cancer (testicular germ cell tumors) | Reactivation of SPANXA2 as a cancer/testis antigen | Detected in seminomas and other germ cell tumors (PMID: 15626745) |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 27.8 | High |
| Other tissues | <0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| NTERA-2 (embryonal carcinoma) | 12.3 | Cancer/testis antigen expression |
| Seminoma cell lines | 8.9 | Reactivation in germ cell tumors |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | <0.01% | Potential loss of start codon; functional impact unknown |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function variants reported in ClinVar or COSMIC.
Gain of Function (GOF)
Not described.
Dominant Negative (DN)
Not described.
View complete mutation data：
Gene Ontology (GO)
| • nucleus (GO:0005634) | • spermatogenesis (GO:0007283) |
| • single fertilization (GO:0007338) | • entry into host cell nucleus (GO:0030260) |
Pathways
• Not assigned to any curated pathway in Reactome or KEGG.
Protein Summary
The SPANXA2 protein is a small, basic nuclear protein (approximately 11 kDa) expressed specifically in the testis. It contains a bipartite nuclear localization signal and is localized to the sperm nucleus. The protein is thought to participate in chromatin remodeling during spermiogenesis and may facilitate sperm nuclear decondensation upon fertilization. Its restricted expression pattern makes it a candidate for cancer/testis antigen-based immunotherapy.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SPANXA2 Knockout HEK293 Cell Line | EDJ-KQ15430 | Human | 728712 | Details Get a Quote |
| SPANXA2 Knockout HeLa Cell Line | EDJ-KQ60721 | Human | 728712 | Details Get a Quote |
| SPANXA2 Knockout A-549 Cell Line | EDJ-KQ69191 | Human | 728712 | Details Get a Quote |
| SPANXA2 Knockout HCT 116 Cell Line | EDJ-KQ77547 | Human | 728712 | Details Get a Quote |
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