Protein
Gene:
SPA17 (official gene symbol)Other symbol:
SPA17CT family:
CT22CT identifier:
CT22Aliases from NCBI:
SP17 , SP17-1RefSeq :
Protein Names (UNIPROT)
Sperm surface protein Sp17
Cellular localization
| Subcellular Localization | Cell type | Methodology | PMID |
|---|---|---|---|
| cytoplasm | brain cancer cells | IHC | 12923251 |
| motile cilia | bronchus and fallopian tubes cells | Immunofluorescence | 18421703 |
| nucleus and cytoplasm | esophageal squamous cell carcinomas cells | IHC | 17230514 |
| cytoplasm | mouse NIH-3T3 cell line | Immunofluorescence | 11415432 |
| cytoplasm | ovarian carcinoma cells | IHC | 14712480 |
| cillia | respiratory airways and reproductive systems cells | IHC | 15034007 |
| cell surface, cytoplasm, around the nucleus | SKOV3 and HO8910 ovarian carcinoma cell lines | Immunofluorescence | 22198696 |
| principal part of the flagellum | sperm | IHC | 15034007 |
| cytoplasm | spermatozoa | IHC | 12923251 |
| principal piece, middle piece and in scattered patches throughout the head | spermatozoa | Immunofluorescence | 15257753 |
Protein function and interaction
SPA17 molecule is shown to bind heparin through its sulphated carbohydrate binding domain (Wen et al., 2001 PMID: 11415432 by similarity). In the testis, this binding ability promotes the adhesion of the spermatozoa to the zona pellucida, the extracellular matrix of the oocyte (Richardson et al., 1994 PMID: 7525387 by similarity).
In vitro precipitation and immunolocalization demonstrate that Sp17 binds to A-kinase anchoring protein 3 (AKAP3) in spermatozoa (Lea et al., 2004 PMID: 15257753). AKAP associated proteins are key molecules in the biochemical machinery regulating the functions of flagella and cilia (Carr et al., 2007 PMID: 17566268) and Sp17 appears to play a regulatory role in a PKA-independent AKAP complex in both male germinal and ciliated somatic cells (Grizzi et al., 2004 PMID: 15034007).
Yeast 2-hybrid system identified Ropporin (ROPN1) as a partner for SP17 protein (Li et al., 2007 PMID: 17551920). Immunoprecipitation assays have shown that SPA17 colocalizes with acetylated tubulin in the cilia layer of the mouse olfactory epithelium (McClintock et al., 2008 PMID: 17971504).
