title: Identification, localization, and functional analysis of the homologues of mouse CABS1 protein in porcine testis.
abstract: Previously, we have identified a calcium-binding protein that is specifically expressed in spermatids and localized to the flagella of the mature sperm in mouse, so-called mCABS1. However, the physiological roles of CABS1 in the male reproductive system have not been fully elucidated yet. In the current study, we aimed to localize and clarify the role of CABS1 in porcine (pCABS1). We determined for the first time the full nucleotides sequence of pCABS1 mRNA. pCABS1 protein was detected on SDS-PAGE gel as two bands at 75 kDa and 70 kDa in adult porcine testis, whereas one band at 70 kDa in epididymal sperm. pCABS1 immunoreactivity in seminiferous tubules was detected in the elongated spermatids, and that in the epididymal sperm was found in the acrosome as well as flagellum. The immunoreactivity of pCABS1 in the acrosomai region disappeared during acrosome reaction. We also identified that pCABS1 has a transmembrane domain using computational prediction of the amino acids sequence. The treatment of porcine capacitated sperm with anti-pCABS1 antiserum significantly decreased acrosome reactions. These results suggest that pCABS1 plays an important role in controlling calcium ion signaling during the acrosome reaction.
authors.affiliation: Laboratory of Reproductive Biochemistry, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Hossam H
authors.initials: HH
authors.lastname: Shawki
authors.forename: Takumi
authors.initials: T
authors.lastname: Kigoshi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Katoh
authors.forename: Manabu
authors.initials: M
authors.lastname: Matsuda
authors.forename: Chioma M
authors.initials: CM
authors.lastname: Ugboma
authors.forename: Satoru
authors.initials: S
authors.lastname: Takahashi
authors.forename: Hisashi
authors.initials: H
authors.lastname: Oishi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kawashima
mesh_terms: D000177:Acrosome / Q000378:metabolism; D020101:Acrosome Reaction / Q000235:genetics / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D020013:Calcium Signaling / Q000235:genetics / Q000502:physiology; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D005407:Flagella / Q000378:metabolism; D008297:Male; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics; D013087:Spermatids / Q000378:metabolism; D013552:Swine; D013737:Testis / Q000378:metabolism*
chemical_list: C542345:CABS1 protein, mouse; D002135:Calcium-Binding Proteins; D012333:RNA, Messenger