Detection of complement C1q receptors on human spermatozoa.
Clq, the first component of the classical complement pathway, is known to play roles in promoting phagocytic events, in addition to its role in activation of complement. Although the molecular events in fertilization leading to the entrance of the spermatozoan into the egg are not well understood, ultrastructural observations suggest that the process is quasi-phagocytic in nature. There is increasing evidence that complement components might play roles in fertilization. Previously, we have shown that C1q promoted the agglutination of capacitated human sperm as well as their adhesion to zona-free hamster eggs. In the present experiments, human spermatozoa were solubilized and, following their phase separation in Triton X-114, subject to 1-D polyacrylamide gel electrophoresis and immunoblotting for the presence of C1q receptors. Both gC1q-R and cC1q-R were detected. In addition, the ability of C1q to promote sperm agglutination was shown to be dependent upon capacitation, suggesting the increased expression of C1q receptors during this process.
Bronson
R
R
Department of Obstetrics, State University of New York at Stony Brook 11794-8091, USA. rbronson@mail.som.sunysb.edu
Bronson
S
S
Oula
L
L
Zhang
W
W
Ghebrehiwet
B
B
D000372:Agglutination Tests; D002352:Carrier Proteins; D006801:Humans; D018960:Hyaluronan Receptors; D008297:Male; D008562:Membrane Glycoproteins; D024101:Mitochondrial Proteins; D011951:Receptors, Complement / Q000032:analysis*; D013075:Sperm Capacitation; D013094:Spermatozoa / Q000737:chemistry* / Q000502:physiology
C087299:C1QBP protein, human; D002352:Carrier Proteins; D018960:Hyaluronan Receptors; D008562:Membrane Glycoproteins; D024101:Mitochondrial Proteins; D011951:Receptors, Complement; C032402:complement 1q receptor