Synthesis of androgen-dependent secretory proteins by rat seminal vesicles

Androgenic steroids control the synthesis and secretion of several proteins by the seminal vesicles of the male rat. Prominent among them are 2 basic proteins, S and F, previously used as markers of androgen action. These proteins are not found among translation products of a wheat-germ protein-synthesising system supplied with mRNA from seminal vesicles of normal rats. Instead, higher molecular weight forms, S' and F', are formed which are nonetheless related antigenically to S and F respectively. Injected into Xenopus Laevis oocytes, seminal vesicle mRNA does direct synthesis and secretion of polypeptides S and F. Partial peptide analysis confirms that S' and F' have extensive amino acid sequence homology with S and F respectively. We conclude that S' and F' are precursor forms of the secreted proteins and thus at least 2 abundant proteins of this male accessory tissue are secreted by a mechanism common to a wide number of secreted proteins.