Stolonidiol: Synthesis, Target Identification, and Mechanism for Choline Acetyltransferase Activation.

Stolonidiol, a marine natural product, has been reported to potentiate the activity of choline acetyltransferase (ChAT), the enzyme that produces the neurotransmitter acetylcholine. Here we report the total synthesis of stolonidiol starting from (R)-(+)-limonene. To identify the mechanism by which ChAT activity is increased, we sought to identify the biological target of stolonidiol. We show that stolonidiol binds to the phorbol ester binding site of protein kinase C (PKC), induces translocation of PKC to the cell membrane, and activates kinase activity. Furthermore, we confirmed the increase in ChAT activity observed upon treatment of cells with stolonidiol and show that this effect is mediated by PKC. Collectively, our data strongly suggest that PKC activation by stolonidiol is responsible for the resulting potentiation of ChAT activity.