title: Improved accumulation of ajmalicine and tetrahydroalstonine in Catharanthus cells expressing an ABC transporter.
abstract: The biosynthetic pathway of monoterpenoid indole alkaloids in Catharanthus roseus is located throughout various membranes at both the cellular and intercellular levels. ATP-binding cassette (ABC) transporters are known to export vincristine and vinblastine from human cancer cells. It has recently been shown that ABC transporters are also involved in the transport of various monoterpenoid alkaloids in Catharanthus roseus cells. Over-expression of an ABC transporter in this plant might therefore affect the regulation of the alkaloid biosynthetic pathway. CjMDR1, an ABC transporter gene originally isolated from Coptis japonica, was expressed in Catharanthus roseus cell cultures. Cells showing a positive PCR signal of the transgene in both cDNA and genomic DNA samples were subject to transport studies using selected substrates. Unexpectedly, transport of the isoquinoline alkaloid berberine, the main substrate of CjMDR1 transporter in Coptis japonica, was not affected as compared with control and wild-type Catharanthus cells. On the other hand, the endogenous alkaloids ajmalicine and tetrahydroalstonine were accumulated significantly more in Catharanthus roseus cells expressing CjMDR1 in comparison with control lines after feeding these alkaloids.
authors.affiliation: Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, PO Box 9502, Leiden 2333 CC, The Netherlands. b.pomahacova.2@umail.leidenuniv.nl
authors.forename: Barbora
authors.initials: B
authors.lastname: Pomahacová
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Dusek
authors.forename: Jirina
authors.initials: J
authors.lastname: Dusková
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Yazaki
authors.forename: Sittiruk
authors.initials: S
authors.lastname: Roytrakul
authors.forename: Robert
authors.initials: R
authors.lastname: Verpoorte
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D001599:Berberine / Q000378:metabolism; D001692:Biological Transport; D030008:Catharanthus / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D046948:Secologanin Tryptamine Alkaloids / Q000378:metabolism*; D019076:Transgenes; D014617:Vacuoles / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D046948:Secologanin Tryptamine Alkaloids; D001599:Berberine; C005709:raubasine