title: Angiotensin-converting enzyme is a GPI-anchored protein releasing factor crucial for fertilization.
abstract: The angiotensin-converting enzyme (ACE) is a key regulator of blood pressure. It is known to cleave small peptides, such as angiotensin I and bradykinin and changes their biological activities, leading to upregulation of blood pressure. Here we describe a new activity for ACE: a glycosylphosphatidylinositol (GPI)-anchored protein releasing activity (GPIase activity). Unlike its peptidase activity, GPIase activity is weakly inhibited by the tightly binding ACE inhibitor and not inactivated by substitutions of core amino acid residues for the peptidase activity, suggesting that the active site elements for GPIase differ from those for peptidase activity. ACE shed various GPI-anchored proteins from the cell surface, and the process was accelerated by the lipid raft disruptor filipin. The released products carried portions of the GPI anchor, indicating cleavage within the GPI moiety. Further analysis by high-performance liquid chromatography-mass spectrometry predicted the cleavage site at the mannose-mannose linkage. GPI-anchored proteins such as TESP5 and PH-20 were released from the sperm membrane of wild-type mice but not in Ace knockout sperm in vivo. Moreover, peptidase-inactivated E414D mutant ACE and also PI-PLC rescued the egg-binding deficiency of Ace knockout sperms, implying that ACE plays a crucial role in fertilization through this activity.
authors.affiliation: Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Suita, 2-2 Yamadaoka, Osaka 565-0871, Japan. kondohg@frontier.kyoto-u.ac.jp
authors.forename: Gen
authors.initials: G
authors.lastname: Kondoh
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Tojo
authors.forename: Yuka
authors.initials: Y
authors.lastname: Nakatani
authors.forename: Nobuyasu
authors.initials: N
authors.lastname: Komazawa
authors.forename: Chie
authors.initials: C
authors.lastname: Murata
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yamagata
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Maeda
authors.forename: Taroh
authors.initials: T
authors.lastname: Kinoshita
authors.forename: Masaru
authors.initials: M
authors.lastname: Okabe
authors.forename: Ryo
authors.initials: R
authors.lastname: Taguchi
authors.forename: Junji
authors.initials: J
authors.lastname: Takeda
mesh_terms: D000818:Animals; D002460:Cell Line; D005306:Fertilization; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D018345:Mice, Knockout; D009865:Oocytes / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism
chemical_list: D017261:Glycosylphosphatidylinositols; D011993:Recombinant Fusion Proteins; D007703:Peptidyl-Dipeptidase A