title: Mouse uterine 24p3 protein as a suppressor of sperm acrosome reaction.
abstract: Under in vitro conditions, incubation with 0.3% bovine serum albumin (BSA) and 1.8 mM CaCl(2) induces mouse sperm capacitation and increases the consequential acrosome-reaction. The effect of mouse uterine 24p3 protein on such stimulated sperm has been investigated to understand the biological function of the 24p3 protein. Variations in the intracellular pH (pHi), calcium concentration, cAMP levels and tyrosine phosphorylation in cytosol were determined and on in vitro mouse fertilization was evaluated. The presence of 24p3 protein reduced the response of sperm to BSA and calcium by suppressing the elevation of intracellular pH, calcium uptake, cAMP accumulation and protein tyrosine phosphorylation of BSA/calcium-stimulated sperm and showed inhibitory effect on mouse in vitro fertilization. The results indicated the inhibition of the BSA-stimulated sperm acrosome reaction by 24p3 protein then suppressed sperm fertilization. We suggested that the 24p3 protein acts as an in vitro inhibitor of the acrosome reaction in BSA stimulated sperm and this might be an anti-fertilization factor in vitro.
authors.affiliation: Institute of Biological Chemistry, Academia Sinica, Post Box 23-106, Taipei, Taiwan.
authors.forename: Ying-Chu
authors.initials: YC
authors.lastname: Lee
authors.forename: Namasivayam
authors.initials: N
authors.lastname: Elangovan
authors.forename: Woan-Fang
authors.initials: WF
authors.lastname: Tzeng
authors.forename: Sin-Tak
authors.initials: ST
authors.lastname: Chu
mesh_terms: D020101:Acrosome Reaction / Q000502:physiology*; D000209:Acute-Phase Proteins / Q000378:metabolism* / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D002122:Calcium Chloride; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D005306:Fertilization / Q000502:physiology*; D005307:Fertilization in Vitro; D005434:Flow Cytometry; D006863:Hydrogen-Ion Concentration; D000071068:Lipocalin-2; D054834:Lipocalins; D008297:Male; D051379:Mice; D015513:Oncogene Proteins / Q000378:metabolism* / Q000502:physiology; D010766:Phosphorylation; D012710:Serum Albumin, Bovine; D013094:Spermatozoa / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism; D014599:Uterus / Q000737:chemistry
chemical_list: D000209:Acute-Phase Proteins; D000071068:Lipocalin-2; D054834:Lipocalins; D015513:Oncogene Proteins; C071332:Lcn2 protein, mouse; D012710:Serum Albumin, Bovine; D014443:Tyrosine; D000242:Cyclic AMP; D002122:Calcium Chloride