Recognition of a human sperm surface protein involved in the progesterone-initiated acrosome reaction by antisera against an endomembrane progesterone binding protein from porcine liver.
Antisera against a porcine liver endomembrane progesterone (P4)-binding protein inhibited the P4-initiated acrosome reaction (AR) but not the ionomycin-initiated AR of human sperm. Indirect immunofluorescence studies detected antigen in the sperm head that moved during capacitation from a posterior head region to a midhead region. Moreover, the antisera detected a 44.6 kDa protein in western blots of sperm digitonin extracts. These results suggest that a sperm protein with at least partial homology to the liver endomembrane P4-binding protein, is a putative P4-receptor on the sperm plasma membrane involved in the P4-initiated AR.
Buddhikot
M
M
Department of Cell Biology and Human Anatomy, University of California, School of Medicine, Davis 95616-8643, USA.
Falkenstein
E
E
Wehling
M
M
Meizel
S
S
D020101:Acrosome Reaction / Q000502:physiology; D000818:Animals; D015153:Blotting, Western; D005455:Fluorescent Antibody Technique; D006801:Humans; D007106:Immune Sera; D008099:Liver / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism*; D011376:Progesterone-Binding Globulin / Q000276:immunology / Q000378:metabolism*; D013075:Sperm Capacitation / Q000502:physiology; D013077:Sperm Head / Q000378:metabolism*; D013094:Spermatozoa / Q000378:metabolism*; D013552:Swine
D007106:Immune Sera; D008565:Membrane Proteins; D011376:Progesterone-Binding Globulin; D011374:Progesterone