Hormonal regulation of protein synthesis, secretion, and phosphorylation in cultured rat Sertoli cells.

Publisher Website
Google Scholar
Abstract
The accumulation of 2 polypeptides, SCm1 and SCm2, in the medium of Sertoli cell cultures is enhanced by FSH but is unaffected by either the cAMP analog, N6,O2''-dibutyryl cAMP or luteinizing hormone [LH]. The assigned MW of SCm1 and SCm2 differ from those of androgen-binding protein subunits or any other previously identified Sertoli cell secretory product. Incubation of Sertoli cell cultures with either FSH or N6,O2''-dibutyryl cAMP also stimulates the incorporation of [35S]methionine into 2 intracellular polypeptides, SCc1 and SCc2. In addition, the phosphorylation of 3 intracellular polypeptides, SCc3, SCc4 and SCc5, is intensified when Sertoli cell cultures are treated with either FSH or N6,O2''-dibutyryl cAMP. Based on these results and on previous work, SCm1 and SCm2 may, like androgen-binding protein, be secreted by Sertoli cells and function extracellularly while SCc1 and SCc2 are involved in FSH-dependent intracellular activity; SCc3, SCc4 and SCc5 are possible substrates for FSH-stimulated, cAMP-dependent protein kinase activity; and SCc5 is an isoelectric variant of vimentin-type intermediate filament protein presumably involved in FSH- and N6,O2''-dibutyryl cAMP-induced Sertoli cell shape changes.