title: Seminal CD38 Enhances Human Sperm Capacitation through Its Interaction with CD31.
abstract: Human sperm have to undergo a maturational process called capacitation in the female reproductive tract. Capacitation confers upon the sperm an ability to gain hypermotility and undergo acrosome reaction. Previous studies have suggested that seminal plasma proteins induce the capacitation of sperm in the female reproductive tract for the successful fertilization of the oocyte. However, the function of seminal plasma proteins in capacitation remains largely unclear. To the end, we found that soluble CD38 (sCD38) in seminal plasma increases the capacitation of sperm via specific interactions between sCD38 and the CD31 on the sperm. Upon the association of sCD38 with CD31, tyrosine kinase Src phosphorylates CD31, a process blocked by Src inhibitors. Shc, SHP-2, Grb2, and SOS, as well as Src kinase were found to associate with the phosphorylated CD31. The sCD38-induced phosphorylation of CD31 initiates a cascade reaction through the phosphorylation of Erk1/2, which results in the acrosome reaction, and sperm hypermotility. These processes were prevented by Src, Ras and MEK inhibitors. Taken together, these data indicate that the sCD38 present in seminal plasma plays a critical role in the capacitation of sperm.
authors.affiliation: National Creative Research Laboratory for Ca2+ Signaling Network, Chonbuk National University Medical School, Jeonju, 561-180, Korea; Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Korea.
authors.forename: Byung-Ju
authors.initials: BJ
authors.lastname: Kim
authors.affiliation: National Creative Research Laboratory for Ca2+ Signaling Network, Chonbuk National University Medical School, Jeonju, 561-180, Korea; Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Korea.
authors.forename: Dae-Ryoung
authors.initials: DR
authors.lastname: Park
authors.affiliation: National Creative Research Laboratory for Ca2+ Signaling Network, Chonbuk National University Medical School, Jeonju, 561-180, Korea; Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Korea.
authors.forename: Tae-Sik
authors.initials: TS
authors.lastname: Nam
authors.affiliation: National Creative Research Laboratory for Ca2+ Signaling Network, Chonbuk National University Medical School, Jeonju, 561-180, Korea; Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Korea.
authors.forename: Seo Ho
authors.initials: SH
authors.lastname: Lee
authors.affiliation: National Creative Research Laboratory for Ca2+ Signaling Network, Chonbuk National University Medical School, Jeonju, 561-180, Korea; Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Korea; Institute of Cardiovascular Research, Chonbuk National University, Jeonju, Korea.
authors.forename: Uh-Hyun
authors.initials: UH
authors.lastname: Kim
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism*; D020101:Acrosome Reaction; D006801:Humans; D020935:MAP Kinase Signaling System; D008297:Male; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism*; D011485:Protein Binding; D012661:Semen / Q000378:metabolism*; D012995:Solubility; D013075:Sperm Capacitation; D013081:Sperm Motility
chemical_list: D019408:Platelet Endothelial Cell Adhesion Molecule-1; D019000:Phosphotyrosine; D051997:ADP-ribosyl Cyclase 1