Ligation of the C1q receptor, gC1qR/p33, associates with both the α vβ 3 integrin and vitronectin and causes protein phosphorylation

Abstract

Objective: Recent evidence indicates that certain complement components may play a specific role in mammalian fertilization. C1q, the first molecule in the classical complement cascade, has the ability to promote sperm agglutination as well as altering sperm-oolemma binding and fusion. We have previously detected an increase in the expression of its receptor, gC1qR, over the rostral portion of the sperm head, occurring after capacitation, and have shown that its ligation leads to an increase in intracellular calcium and acrosomal exocytosis.