EFFECTS OF METHIONINE AND S-ADENOSYLMETHIONINE ON PRODUCTION OF 1-METHYLADENINE IN STARFISH FOLLICLE CELLS.

Incubation of follicle cells of the starfish (Asterias amurensis) with a gonad-stimulating hormonal peptide (GSS) leads to the production of 1-methyladenine. the trigger of oocyte maturation. Addition of L-methionine to the incubation medium promotes the production of 1-methyladenine. This study shows that S-adenosylmethionine also enhances the production of 1-methyladenine in such an incubation mixture. However, in the absence of GSS, addition of S-adenosylmethionine failed to produce an appreciable amount of 1-methyladenine. When an homogenate of isolated follicle cells was incubated, a certain amount of 1-methyladenine was produced, whether or not GSS was present. Addition of S-adenosylmethionine to the incubation mixture of follicle homogenate enhanced the production of 1-methyladenine. Although addition of adenosine triphosphate (ATP) to such an incubation mixture had little effect in producing 1-methyladenine, it exerted a promoting effect on 1-methyladenine production when S-adenosyl-methionine was present. These results suggest that methionine, through its active form, S-adenosylmethionine, acts as a donor of methyl group in the formation of 1-methyladenine.