Taxus NPF transporter involved in the uptake of 10-deacetylbaccatin III facilitates the biosynthesis of taxane compounds

Abstract

Paclitaxel is an anticancer diterpene derivative produced by yew trees (Taxus spp.) as a forest resource. The biosynthetic pathway in Taxus spp. consists of intricate enzyme reactions, which involve many acylation steps on the taxadiene core structure. Time course analysis of the culture medium of yew cell suspension cultures revealed the dynamics of relevant taxane compounds, suggesting the active movement of biosynthetic intermediates across the plasma membrane leading to paclitaxel formation. Here, we report the identification of a yew NPF-type transporter, NPF2.1, involved in the uptake of 10-deacetylbaccatin III as a proton symporter. Expression of NPF2.1 in yeast facilitated the in vivo acetylation of 10-deacetylbaccatin III. In YPD culture media, 10-deacetylbaccatin III (0.1 mg L⁻¹) was effectively converted to the acetylated product within 5 days at pH 5.3. The NPF2.1-mediated yeast bioconversion system was then used for gene discovery studies, which identified a novel BAHD acyltransferase that exhibited acylation activity with broad substrate specificity for acyl donors. These results suggest that the application of yeast NPF2.1 is a powerful molecular tool for the discovery of new paclitaxel biosynthetic genes and also for the production of paclitaxel in a synthetic biology approach.