T-SP1: a novel serine protease-like protein predominantly expressed in testis.
Here, we describe a novel member in the group of membrane-anchored chymotrypsin (S1)-like serine proteases, namely testis serine protease 1 (T-SP1), as it is principally expressed in testis tissue. The human T-SP1 gene encompasses 28.7 kb on the short arm of chromosome 8 and consists of seven exons. Rapid amplification of cDNA ends (RACE) experiments revealed that due to alternative splicing three different variants (T-SP1/1, -2, -3) are detectable in testis tissue displaying pronounced heterogeneity at their 3'-end. T-SP1/1 consists of an 18 amino acid signal peptide and of a 49 amino acid propeptide. The following domain with the catalytic triad of His(108), Asp(156), and Ser(250) shares sequence identities of 42% and 40% with the blood coagulation factor XI and plasma kallikrein, respectively. Only T-SP1/1 contains a hydrophobic part at the C-terminus, which provides the basis for cell membrane anchoring. Using a newly generated polyclonal anti-T-SP1 antibody, expression of the T-SP1 protein was found in the Leydig and Sertoli cells of the testis and in the epithelial cells of the ductuli efferentes. Notably, T-SP1 protein was also detectable in prostate cancer and in some ovarian cancer tissues, indicating tumor-related synthesis of T-SP1 beyond testis tissue.
Neth
Peter
P
Division of Clinical Chemistry and Clinical Biochemistry, Department of Surgery, Ludwig Maximilians University, D-80336 Munich, Germany. Peter.Neth@med.uni-muenchen.de
Profanter
Birgit
B
Geissler
Claudia
C
Nägler
Dorit K
DK
Nerlich
Andreas
A
Sommerhoff
Christian P
CP
Jochum
Marianne
M
D000595:Amino Acid Sequence; D015153:Blotting, Western; D002460:Cell Line; D003001:Cloning, Molecular; D019295:Computational Biology; D004543:Ejaculatory Ducts / Q000166:cytology / Q000201:enzymology; D004847:Epithelial Cells / Q000201:enzymology; D004926:Escherichia coli / Q000378:metabolism; D005091:Exons / Q000235:genetics; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007438:Introns / Q000235:genetics; D007985:Leydig Cells / Q000201:enzymology; D008297:Male; D008969:Molecular Sequence Data; D010051:Ovarian Neoplasms / Q000201:enzymology; D011471:Prostatic Neoplasms / Q000201:enzymology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012697:Serine Endopeptidases / Q000096:biosynthesis* / Q000235:genetics*; D012708:Sertoli Cells / Q000201:enzymology; D013737:Testis / Q000378:metabolism*
C534737:Prss55 protein, human; D012333:RNA, Messenger; D011994:Recombinant Proteins; D012697:Serine Endopeptidases