title: Characterization of lactoferrin receptor on human spermatozoa.
abstract: Lactoferrin (LF) is abundant in human seminal plasma and on sperm surfaces. However, lactoferrin receptor (LFR) on human spermatozoa has not yet been reported. To study the expression, localization and characteristics of LFR on human spermatozoa, different experimental approaches were applied: LFR gene was amplified from a human testis cDNA library and recombinant LFR (rLFR) protein was produced in the expression vector Escherichia coli BL21 (DE3); human sperm membrane proteins were extracted and analysed via Western blot; the binding of LF to LFR was investigated by Far-Western blot, immunoprecipitation and autoradiography analysis and the localization of LFR on sperm surfaces was detected using immunofluorescence. LFR gene was amplified from a human testis cDNA library and the molecular weight of rLFR was 34kDa. The native LFR on human spermatozoa was a 136-kDa tetramer which was anchored to the sperm head and mid-piece through glycophosphatidylinositol. LF could bind to LFR competitively in vitro. As far as is known, this study has elucidated for the first time that LFR was expressed at the testis level, was anchored to the sperm membrane by glycophosphatidylinositol during spermatogenesis. LFR may play important roles through binding to and mediating LF.
authors.affiliation: Laboratory of Reproductive Medicine, Department of Urology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Bianjiang
authors.initials: B
authors.lastname: Liu
authors.forename: Zengjun
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Niu
authors.forename: Shifeng
authors.initials: S
authors.lastname: Su
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Xinru
authors.initials: X
authors.lastname: Wang
mesh_terms: D000818:Animals; D026481:Blotting, Far-Western; D015153:Blotting, Western; D005455:Fluorescent Antibody Technique; D015723:Gene Library; D017261:Glycosylphosphatidylinositols / Q000737:chemistry; D006801:Humans; D007781:Lactoferrin / Q000378:metabolism; D008297:Male; D051379:Mice; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: D017261:Glycosylphosphatidylinositols; D011956:Receptors, Cell Surface; C038340:lactoferrin receptors; D007781:Lactoferrin