Zinc finger proteins act as transcriptional repressors of alkaloid biosynthesis genes in Catharanthus roseus.
In Catharanthus roseus cell suspensions, the expression of several terpenoid indole alkaloid biosynthetic genes, including two genes encoding strictosidine synthase (STR) and tryptophan decarboxylase (TDC), is coordinately induced by fungal elicitors such as yeast extract. To identify molecular mechanisms regulating the expression of these genes, a yeast one-hybrid screening was performed with an elicitor-responsive part of the TDC promoter. This screening identified three members of the Cys(2)/His(2)-type (transcription factor IIIA-type) zinc finger protein family from C. roseus, ZCT1, ZCT2, and ZCT3. These proteins bind in a sequence-specific manner to the TDC and STR promoters in vitro and repress the activity of these promoters in trans-activation assays. In addition, the ZCT proteins can repress the activating activity of APETALA2/ethylene response-factor domain transcription factors, the ORCAs, on the STR promoter. The expression of the ZCT genes is rapidly induced by yeast extract and methyljasmonate. These results suggest that the ZCT proteins act as repressors in the regulation of elicitor-induced secondary metabolism in C. roseus.
Pauw
Bea
B
Institute of Biology, Leiden University, Clusius Laboratory, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands.
Hilliou
Frédérique A O
FA
Martin
Virginia Sandonis
VS
Chatel
Guillaume
G
de Wolf
Cocky J F
CJ
Champion
Antony
A
Pré
Martial
M
van Duijn
Bert
B
Kijne
Jan W
JW
van der Fits
Leslie
L
Memelink
Johan
J
D000470:Alkaloids / Q000378:metabolism; D000595:Amino Acid Sequence; D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000235:genetics; D015152:Blotting, Northern; D019759:Carbon-Nitrogen Lyases / Q000235:genetics; D030008:Catharanthus / Q000378:metabolism*; D003517:Cyclopentanes / Q000737:chemistry; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D005030:Ethylenes / Q000737:chemistry; D005822:Genetic Vectors; D008954:Models, Biological; D008969:Molecular Sequence Data; D054883:Oxylipins; D010940:Plant Proteins / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D020798:Two-Hybrid System Techniques; D016335:Zinc Fingers
D000470:Alkaloids; D003517:Cyclopentanes; D018076:DNA, Complementary; D005030:Ethylenes; D054883:Oxylipins; D010940:Plant Proteins; D012333:RNA, Messenger; D012313:RNA; C011006:jasmonic acid; D004247:DNA; C036216:ethylene; D001142:Aromatic-L-Amino-Acid Decarboxylases; D019759:Carbon-Nitrogen Lyases; C022684:strictosidine synthetase