Testis Serine Protease 1 (TESSP1)

TESSP-1 was cloned using mRNA isolated from the adult mouse testis. The open reading frame of this cDNA codes for a protein of 322 amino acids, which includes a hydrophobic signal peptide of 18 amino acids and an N-terminal activation peptide of 34 amino acids. The protein has an additional hydrophobic amino acid sequence at the C-terminus. Expression of the TESSP-1 gene was restricted to the testis. TESSP-1 mRNA expression initiated in the mouse testis at 2 weeks after birth, and its level increased steadily with sexual maturation of the animal. In situ hybridization analysis revealed that TESSP-1 mRNA was expressed in type B spermatogonia and spermatocytes at stages between preleptotene and pachytene. The testis contained at least five distinct forms of TESSP-1 transcript, which presumably resulted from alternative splicing of the mRNA.