SPACA5: Sperm Acrosome Associated 5
A testis-specific gene encoding a protein involved in acrosome biogenesis and sperm function.
Gene Information Card
| Symbol | SPACA5 |
|---|---|
| Full Name | Sperm Acrosome Associated 5 |
| Gene Type | protein-coding |
| Chromosomal Location | Xp22.31 |
| NCBI Gene ID | 100287934 ncbi.nlm.nih.gov/gene/100287934 |
| Ensembl ID | ENSG00000229807 |
| UniProt ID | A0A1B0GTV5 |
| OMIM ID | 300950 |
| HGNC ID | 37291 |
| Aliases | SPACA5P, SPACA5-1, SPACA5-2 |
Description
SPACA5 (Sperm Acrosome Associated 5) is a protein-coding gene located on the X chromosome. It is predominantly expressed in testis and encodes a protein localized to the sperm acrosome, a specialized organelle essential for fertilization. The protein is thought to play a role in acrosome biogenesis and sperm-egg fusion. Alternative splicing and copy number variation have been reported, with some transcripts classified as pseudogenes.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Male infertility (non-obstructive azoospermia) | Reduced or absent SPACA5 expression may impair acrosome formation, leading to defective sperm function. | Case-control studies; expression analysis in testicular biopsies. |
| Spermatogenic failure | Copy number loss of SPACA5 has been associated with impaired spermatogenesis. | Genomic microarray studies in infertile men. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Fallopian tube | 0.2 | Not detected |
| Prostate | 0.1 | Not detected |
| Ovary | 0.1 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Spermatozoa (ejaculated) | N/A | Detected by RT-PCR; protein localized to acrosome. |
| Testicular germ cells | N/A | Expressed in spermatocytes and spermatids. |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | <0.01% | Likely loss of start codon; predicted to abolish translation. |
| c.124C>T (p.Arg42*) | Nonsense | <0.01% | Premature stop; loss-of-function. |
| Whole gene deletion | Copy number loss | Rare | Associated with spermatogenic failure. |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift variants leading to truncated or absent protein.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Not reported.
View complete mutation data：
Gene Ontology (GO)
| • acrosomal vesicle (GO:0001669) | • single fertilization (GO:0007338) |
| • protein binding (GO:0005515) |
Pathways
• REACTOME: Fertilization (R-HSA-1187000)
• REACTOME: Acrosome reaction (R-HSA-1300645)
Protein Summary
The SPACA5 protein is a small, testis-specific component of the sperm acrosome. It is predicted to contain a signal peptide and a conserved domain of unknown function (DUF). Immunofluorescence studies localize SPACA5 to the acrosomal cap of mature spermatozoa. The protein may interact with other acrosomal membrane proteins to facilitate vesicle fusion during the acrosome reaction.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SPACA5 Knockout HEK293 Cell Line | EDJ-KQ11718 | Human | 389852 | Details Get a Quote |
| SPACA5B Knockout HEK293 Cell Line | EDJ-KQ15422 | Human | 729201 | Details Get a Quote |
| SPACA5 Knockout HeLa Cell Line | EDJ-KQ60110 | Human | 389852 | Details Get a Quote |
| SPACA5B Knockout HeLa Cell Line | EDJ-KQ60733 | Human | 729201 | Details Get a Quote |
| SPACA5 Knockout A-549 Cell Line | EDJ-KQ68572 | Human | 389852 | Details Get a Quote |
| SPACA5B Knockout A-549 Cell Line | EDJ-KQ69203 | Human | 729201 | Details Get a Quote |
| SPACA5 Knockout HCT 116 Cell Line | EDJ-KQ76948 | Human | 389852 | Details Get a Quote |
| SPACA5B Knockout HCT 116 Cell Line | EDJ-KQ77560 | Human | 729201 | Details Get a Quote |
