Follicle stimulating hormone regulation of protein kinase activity and protein synthesis in testis

Incubation of testis tubules containing predominantly Sertoli cells (SCE) with Follicle Stimulating Hormone results in a rapid activation of cyclic AMP dependent protein kinase. Multiple forms of soluble protein kinase were shown to exist in Sertoli cell cytosol by DEAE chromatography. Evidence suggests that only one of the two cyclic AMP dependent forms is activated by FSH. In addition FSH stimulates testicular protein synthesis and induces the accumulation of a specific Sertoli cell protein, ABP. Kinetic studies reveal this induction to be selective. Moreover, stimulation of ABP can also be accomplished by injection of a derivative of cyclic AMP. These effects are inhibited by prior treatment of the animals with cycloheximide or actinomycin D. Thus, FSH appears to induce de novo synthesis of ABP in a manner which requires prior stimulation of a transcriptional event. Finally, FSH is shown to increase the concentration of Sertoli cell mRNA assayed in a heterologous cell free protein synthesizing system. Comparison of the time course of stimulation of mRNA and ABP in response to FSH leads to the possibility that the former is required for the latter. The significance of these events with respect to the biochemical actions of peptide hormones is discussed.