Spermatogenesis Associated Protein 2 (SPATA2)

SPATA2 is highly hydrophilic. It has no signal peptide, is serine-rich, and contains 17 cysteine residues that are located predominantly in the C-terminal domain. SPATA2 also has several potential phosphorylation sites, but no N-glycosylation sites. Northern blot analysis detected an abundant transcript of 2.7 kb and a less abundant transcript of 4.0 kb, with highest expression in testis. Weaker expression was detected in spleen, followed by thymus and prostate. SPATA2 was not normally detected in uterus, small intestine, colon, or peripheral blood leukocytes. Western blot analysis of testis cell extracts detected a protein with an apparent molecular mass of 60 kD, as well as a less abundant protein of 46 to 48 kD. Expression of both proteins, especially the smaller protein, was reduced in several testiculopathies.