Prostasin is a glycosylphosphatidylinositol-anchored active serine protease.
A recombinant human prostasin serine protease was expressed in several human cell lines. Subcellular fractionation showed that this serine protease is synthesized as a membrane-bound protein while a free-form prostasin is secreted into the culture medium. Prostasin was identified in nuclear and membrane fractions. Membrane-bound prostasin can be released by phosphatidylinositol-specific phospholipase C treatment, or labeled by [(3)H]ethanolamine, indicating a glycosylphosphatidylinositol anchorage. A prostasin-binding protein was identified in mouse and human seminal vesicle fluid. Both the secreted and the membrane-bound prostasin were able to form a covalently linked 82-kDa complex when incubated with seminal vesicle fluid. The complex formation between prostasin and the prostasin-binding protein was inhibited by a prostasin antibody, heparin, and serine protease inhibitors. Prostasin's serine protease activity was inhibited when bound to the prostasin-binding protein in mouse seminal vesicle fluid. This study indicates that prostasin is an active serine protease in its membrane-bound form.
Department of Molecular Biology, University of Central Florida, Orlando, Florida 32816, USA.
L M
LM
Chen
M L
ML
Skinner
S W
SW
Kauffman
J
J
Chao
L
L
Chao
C D
CD
Thaler
K X
KX
Chai
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D002467:Cell Nucleus / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D019856:Ethanolamine / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D051379:Mice; D008970:Molecular Weight; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D011471:Prostatic Neoplasms / Q000201:enzymology; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012669:Seminal Vesicles / Q000201:enzymology / Q000378:metabolism; D012697:Serine Endopeptidases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014162:Transfection; D014316:Tritium; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000378:metabolism; D000099271:Prostasin
D019856:Ethanolamine; D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D011994:Recombinant Proteins; D012697:Serine Endopeptidases; D014316:Tritium; D010738:Type C Phospholipases; D000099271:Prostasin