Sperm-associated antigen 6 is a protein that in humans is encoded by the SPAG6gene.[1][2]
Function
The correlation of anti-sperm antibodies with cases of unexplained infertility implicates a role for these antibodies in blocking fertilization. Improved diagnosis and treatment of immunologic infertility, as well as identification of proteins for targeted contraception, are dependent on the identification and characterization of relevant sperm antigens. The protein expressed by this gene is recognized by anti-sperm antibodies from an infertile man. This protein localizes to the tail of permeabilized human sperm and contains eight contiguous armadillo repeats, a motif known to mediate protein-protein interactions. Studies in mice suggest that this protein is involved in sperm flagellar motility and maintenance of the structural integrity of mature sperm. Alternatively spliced variants that encode different protein isoforms have been described but the full-length sequences of only two have been determined.[2]
References
↑Neilson LI, Schneider PA, Van Deerlin PG, Kiriakidou M, Driscoll DA, Pellegrini MC, Millinder S, Yamamoto KK, French CK, Strauss JF (September 1999). "cDNA cloning and characterization of a human sperm antigen (SPAG6) with homology to the product of the Chlamydomonas PF16 locus". Genomics. 60 (3): 272–80. doi:10.1006/geno.1999.5914. PMID10493827.
Diekman AB, Herr JC (January 1997). "Sperm antigens and their use in the development of an immunocontraceptive". American Journal of Reproductive Immunology. 37 (1): 111–7. doi:10.1111/j.1600-0897.1997.tb00199.x. PMID9138444.
Sapiro R, Tarantino LM, Velazquez F, Kiriakidou M, Hecht NB, Bucan M, Strauss JF (March 2000). "Sperm antigen 6 is the murine homologue of the Chlamydomonas reinhardtii central apparatus protein encoded by the PF16 locus". Biology of Reproduction. 62 (3): 511–8. doi:10.1095/biolreprod62.3.511. PMID10684790.
Ficarro S, Chertihin O, Westbrook VA, White F, Jayes F, Kalab P, Marto JA, Shabanowitz J, Herr JC, Hunt DF, Visconti PE (March 2003). "Phosphoproteome analysis of capacitated human sperm. Evidence of tyrosine phosphorylation of a kinase-anchoring protein 3 and valosin-containing protein/p97 during capacitation". The Journal of Biological Chemistry. 278 (13): 11579–89. doi:10.1074/jbc.M202325200. PMID12509440.