CaaX-prenyltransferases are essential for expression of genes involvedin the early stages of monoterpenoid biosynthetic pathway in Catharanthus roseus cells.
CaaX-prenyltransferases (CaaX-PTases) catalyse the covalent attachment of isoprenyl groups to conserved cysteine residues located at the C-terminal CaaX motif of a protein substrate. This post-translational modification is required for the function and/or subcellular localization of some transcription factors and components of signal transduction and membrane trafficking machinery. CaaX-PTases, including protein farnesyltransferase (PFT) and type-I protein geranylgeranyltransferase (PGGT-I), are heterodimeric enzymes composed of a common alpha subunit and a specific beta subunit. We have established RNA interference cell lines targeting the beta subunits of PFT and PGGT-I, respectively, in the Catharanthus roseus C20D cell line, which synthesizes monoterpenoid indole alkaloids in response to auxin depletion from the culture medium. In both types of RNAi cell lines, expression of a subset of genes involved in the early stage of monoterpenoid biosynthetic pathway (ESMB genes), including the MEP pathway, is strongly decreased. The role of CaaX-PTases in ESMB gene regulation was confirmed by using the general prenyltransferase inhibitor s-perillyl alcohol (SP) and the specific PFT inhibitor Manumycin A on the wild type line. Furthermore, supplementation of SP inhibited cells with monoterpenoid intermediates downstream of the steps encoded by the ESMB genes restores monoterpenoid indole alkaloids biosynthesis. We conclude that protein targets for both PFT and PGGT-I are required for the expression of ESMB genes and monoterpenoid biosynthesis in C. roseus, this represents a non previously described role for protein prenyltransferase in plants.
Courdavault
Vincent
V
Biomolecules et Biotechnologies Vegetales, Labaratoire de Physiologie Vegetale, UFR Science et Techniques, Universite Francois-Rabelais de Tours, EA2106, 37200 , Parc de Grandmont, Tours, France.
Thiersault
Martine
M
Courtois
Martine
M
Gantet
Pascal
P
Oudin
Audrey
A
Doireau
Pierre
P
St-Pierre
Benoit
B
Giglioli-Guivarc'h
Nathalie
N
D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D015152:Blotting, Northern; D030008:Catharanthus / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D018929:Cell Culture Techniques; D048708:Cell Growth Processes / Q000235:genetics; D015536:Down-Regulation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics*; D008969:Molecular Sequence Data; D039821:Monoterpenes / Q000378:metabolism* / Q000494:pharmacology; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D017368:Protein Prenylation / Q000187:drug effects; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference / Q000502:physiology; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D046948:Secologanin Tryptamine Alkaloids / Q000378:metabolism; D013997:Time Factors
D004791:Enzyme Inhibitors; D039821:Monoterpenes; D010940:Plant Proteins; D021122:Protein Subunits; D018749:RNA, Plant; D046948:Secologanin Tryptamine Alkaloids; C032208:perillyl alcohol; D019883:Alkyl and Aryl Transferases; C083291:geranylgeranyltransferase type-I