TY - JOUR

T1 - Iridoid synthase activity is common among the plant progesterone 5β-reductase family

AU - Munkert, Jennifer

AU - Pollier, Jacob

AU - Miettinen, Karel

AU - Van Moerkercke, Alex

AU - Payne, Richard

AU - Müller-Uri, Frieder

AU - Burlat, Vincent

AU - O'Connor, Sarah E.

AU - Memelink, Johan

AU - Kreis, Wolfgang

AU - Goossens, Alain

N1 - Funding Information: The research leading to these results has received funding from the European Union Seventh Framework Programme FP7/2007-2013 under grant agreement number 222716 -SMARTCELL, the Short-Term Scientific Missions (STSM) program from the European Union COST Action FA1006-PlantEngine , the European Molecular Biology Organization (Long-Term Fellowship to A.V.M.) and European Commission support from Marie Curie Actions (EMBOCOFUND2010, GA-2010-267154 to A.V.M.). J.P. is a postdoctoral fellow of the Research Foundation Flanders (FWO). R.P. is supported by a John Innes Centre studentship. Publisher Copyright: © 2015 The Author.

PY - 2015

Y1 - 2015

N2 - Catharanthus roseus, the Madagascar periwinkle, synthesizes bioactive monoterpenoid indole alkaloids, including the anti-cancer drugs vinblastine and vincristine. The monoterpenoid branch of the alkaloid pathway leads to the secoiridoid secologanin and involves the enzyme iridoid synthase (IS), a member of the progesterone 5β-reductase (P5βR) family. IS reduces 8-oxogeranial to iridodial. Through transcriptome mining, we show that IS belongs to a family of six C. Roseus P5βR genes. Characterization of recombinant CrP5βR proteins demonstrates that all but CrP5βR3 can reduce progesterone and thus can be classified as P5βRs. Three of them, namely CrP5βR1, CrP5βR2, and CrP5βR4, can also reduce 8-oxogeranial, pointing to a possible redundancy with IS (corresponding to CrP5βR5) in secoiridoid synthesis. In-depth functional analysis by subcellular protein localization, gene expression analysis, in situ hybridization, and virus-induced gene silencing indicate that besides IS, CrP5βR4 may also participate in secoiridoid biosynthesis. We cloned a set of P5βR genes from angiosperm plant species not known to produce iridoids and demonstrate that the corresponding recombinant proteins are also capable of using 8-oxogeranial as a substrate. This suggests that IS activity is intrinsic to angiosperm P5βR proteins and has evolved early during evolution.

AB - Catharanthus roseus, the Madagascar periwinkle, synthesizes bioactive monoterpenoid indole alkaloids, including the anti-cancer drugs vinblastine and vincristine. The monoterpenoid branch of the alkaloid pathway leads to the secoiridoid secologanin and involves the enzyme iridoid synthase (IS), a member of the progesterone 5β-reductase (P5βR) family. IS reduces 8-oxogeranial to iridodial. Through transcriptome mining, we show that IS belongs to a family of six C. Roseus P5βR genes. Characterization of recombinant CrP5βR proteins demonstrates that all but CrP5βR3 can reduce progesterone and thus can be classified as P5βRs. Three of them, namely CrP5βR1, CrP5βR2, and CrP5βR4, can also reduce 8-oxogeranial, pointing to a possible redundancy with IS (corresponding to CrP5βR5) in secoiridoid synthesis. In-depth functional analysis by subcellular protein localization, gene expression analysis, in situ hybridization, and virus-induced gene silencing indicate that besides IS, CrP5βR4 may also participate in secoiridoid biosynthesis. We cloned a set of P5βR genes from angiosperm plant species not known to produce iridoids and demonstrate that the corresponding recombinant proteins are also capable of using 8-oxogeranial as a substrate. This suggests that IS activity is intrinsic to angiosperm P5βR proteins and has evolved early during evolution.

KW - Catharanthus roseus

KW - Medicago truncatula

KW - monoterpenoid indole alkaloid

KW - progesterone reductase

KW - secoiridoid

KW - VEP1-encoded enone-reductases

U2 - 10.1016/j.molp.2014.11.005

DO - 10.1016/j.molp.2014.11.005

M3 - Journal article

C2 - 25578278

AN - SCOPUS:84925059997

VL - 8

SP - 136

EP - 152

JO - Molecular Plant

JF - Molecular Plant

SN - 1674-2052

IS - 1

ER -