TY - JOUR
T1 - Localization and in-vivo characterization of Thapsia garganica CYP76AE2 indicates a role in thapsigargin biosynthesis
AU - Andersen, Trine Bundgaard
AU - Martinez-Swatson, Karen Agatha
AU - Rasmussen, Silas Anselm
AU - Boughton, Berin Alain
AU - Jørgensen, Kirsten
AU - Andersen-Ranberg, Johan
AU - Nyberg, Nils
AU - Christensen, Søren Brøgger
AU - Simonsen, Henrik Toft
PY - 2017
Y1 - 2017
N2 - The Mediterranean plant Thapsia garganica (dicot, Apiaceae), also known as deadly carrot, produces the highly toxic compound thapsigargin. This compound is a potent inhibitor of the sarcoplasmic-endoplasmic reticulum Ca2+ -ATPase calcium pump in mammals and is of industrial importance as the active moiety of the anticancer drug mipsagargin, currently in clinical trials. Knowledge of thapsigargin in planta storage and biosynthesis has been limited. Here, we present the putative second step in thapsigargin biosynthesis, by showing that the cytochrome P450 TgCYP76AE2, transiently expressed in Nicotiana benthamiana, converts epikunzeaol into epidihydrocostunolide. Furthermore, we show that thapsigargin is likely to be stored in secretory ducts in the roots. Transcripts from TgTPS2 (epikunzeaol synthase) and TgCYP76AE2 in roots were found only in the epithelial cells lining these secretory ducts. This emphasizes the involvement of these cells in the biosynthesis of thapsigargin. This study paves the way for further studies of thapsigargin biosynthesis.
AB - The Mediterranean plant Thapsia garganica (dicot, Apiaceae), also known as deadly carrot, produces the highly toxic compound thapsigargin. This compound is a potent inhibitor of the sarcoplasmic-endoplasmic reticulum Ca2+ -ATPase calcium pump in mammals and is of industrial importance as the active moiety of the anticancer drug mipsagargin, currently in clinical trials. Knowledge of thapsigargin in planta storage and biosynthesis has been limited. Here, we present the putative second step in thapsigargin biosynthesis, by showing that the cytochrome P450 TgCYP76AE2, transiently expressed in Nicotiana benthamiana, converts epikunzeaol into epidihydrocostunolide. Furthermore, we show that thapsigargin is likely to be stored in secretory ducts in the roots. Transcripts from TgTPS2 (epikunzeaol synthase) and TgCYP76AE2 in roots were found only in the epithelial cells lining these secretory ducts. This emphasizes the involvement of these cells in the biosynthesis of thapsigargin. This study paves the way for further studies of thapsigargin biosynthesis.
U2 - 10.1104/pp.16.00055
DO - 10.1104/pp.16.00055
M3 - Journal article
C2 - 28275147
AN - SCOPUS:85018958858
VL - 174
SP - 56
EP - 72
JO - Plant Physiology
JF - Plant Physiology
SN - 0032-0889
IS - 1
ER -