Adenyl cyclase in plasma membrane preparations of sea urchin eggs and its increase in activity after fertilization.

Abstract It has been shown (cf. Robinson et al. , 1968) that adenyl cyclase is present in preparations of plasma membranes from cells of many kinds of animal tissues and that the specific hormones cause, in vivo or in vitro , increased production of cyclic AMP, which is often attributable to increased enzyme activity. The system also has been implicated in chemotactic phenomena ( Konijn et al. , 1968 ). The process of fertilization is known to involve the interaction of specific receptors (fertilizin) on the plasma membrane of the egg with complementary receptors (antifertilizin) on that of the sperm ( Tyler, 1965; Tyler and Tyler, 1966 ). It is of interest, then, to know if adenyl cyclase is present in membrane preparations from sea urchin eggs and if it increases in activity after fertilization. The present results answer both of these questions affirmatively.