Molecular Mechanisms Underlying Sperm-Eng Interaction

In starfish Asterias amurensis，three components in the jelly coat of eggs，namely acrosome reaction-inducing substance(ARIS)，Co-ARIS and asterosap，act in concerted on homologous spermatozoa to elicit the acrosome reaction species-specifically。ARIS is proteoglycan-like compound which binds to the receptor localized to a small domain in the anterior portion of sperm heads。Its activity is mostly attributable to a sulfatedpolysaccharide chain composed of one thousand or so repeating units of a sulfated pentasaccharide.Co-ARIS is a group of saponins consisting of a sulfated steriod and a pentasaccharide。In combination with ARIS，it increases intracellular Ca I D12 I D 1 concentration of sperm.Asterosap is a group of glutamine-rich tetratricontapeptides with a disulfide linkage。It increases cGMP level and intracellular pH of sperm through binding to its receptor that is the guanylate cyclase of 125 kDa in a major sperm membrane protein.

In starfish Asterias amurensis, three components in the jelly coat of eggs, namely acrosome reaction-inducing substance (ARIS), Co-ARIS and asterosap, act in concerted on homologous spermatozoa to elicit the acrosome reaction species-specifically. ARIS is proteoglycan-like compound which binds to the receptor localized to a small domain in the anterior portion of sperm heads. Its activity is mostly attributable to a sulfatedpolysaccharide chain composed of one thousand or so repeating units of a sulfated pentasaccharide. Co-ARIS is a group of saponins consisting of a sulfated steriod and a pentasaccharide. In combination with ARIS, it increases intracellular CaィイD12+ィエD1 concentration of sperm. Asterosap is a group of glutamine-rich tetratricontapeptides with a disulfide linkage. It increases cGMP level and intracellular pH of sperm through binding to its receptor that is the guanylate cyclase of 125 kDa in a major sperm membrane protein.