Functional analysis of a WRKY transcription factor involved in transcriptional activation of the DBAT gene in Taxus chinensis.
ABSTRACT Although the regulation of taxol biosynthesis at the transcriptional level remains unclear, 10-deacetylbaccatin III-10 β-O-acetyl transferase (DBAT) is a critical enzyme in the biosynthesis of taxol. The 1740 bp fragment 5'-flanking sequence of the dbat gene was cloned from Taxus chinensis cells. Important regulatory elements needed for activity of the dbat promoter were located by deletion analyses in T. chinensis cells. A novel WRKY transcription factor, TcWRKY1, was isolated with the yeast one-hybrid system from a T. chinensis cell cDNA library using the important regulatory elements as bait. The gene expression of TcWRKY1 in T. chinensis suspension cells was specifically induced by methyl jasmonate (MeJA). Biochemical analysis indicated that TcWRKY1 protein specifically interacts with the two W-box (TGAC) cis-elements among the important regulatory elements. Overexpression of TcWRKY1 enhanced dbat expression in T. chinensis suspension cells, and RNA interference (RNAi) reduced the level of transcripts of dbat. These results suggest that TcWRKY1 participates in regulation of taxol biosynthesis in T. chinensis cells, and that dbat is a target gene of this transcription factor. This research also provides a potential candidate gene for engineering increased taxol accumulation in Taxus cell cultures.
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ABSTRACT: Over the past decade, Taxol and its closely related structural analogue Taxotere have emerged as very important antitumor agents. Their widespread use in the treatment of a variety of cancer types, their likely approval for the treatment of additional forms of cancer, and their use at earlier stages of intervention will lead to increased demand for these drugs in the future. Because of yield considerations, Taxol and Taxotere are currently derived via semisynthesis from the advanced taxoid 10-deacetylbaccatin III, which must be isolated from yew (Taxus) trees. Thus, efforts are underway to produce Taxol (and other advanced taxoids for use in semisynthesis) by alternate, biotechnological means. This article provides a current overview of research on taxoid biosynthesis and an assessment of bioengineering applications for taxoid production in yew cell culture.Applied Microbiology and Biotechnology 11/2001; 57(1-2):13-9. · 3.69 Impact Factor
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ABSTRACT: PLACE (http://www.dna.affrc.go.jp/htdocs/PLACE/) is a database of nucleotide sequence motifs found in plant cis-acting regulatory DNA elements. Motifs were extracted from previously published reports on genes in vascular plants. In addition to the motifs originally reported, their variations in other genes or in other plant species in later reports are also compiled. Documents for each motif in the PLACE database contains, in addition to a motif sequence, a brief definition and description of each motif, and relevant literature with PubMed ID numbers and GenBank accession numbers where available. Users can search their query sequences for cis-elements using the Signal Scan program at our web site. The results will be reported in one of the three forms. Clicking the PLACE accession numbers in the result report will open the pertinent motif document. Clicking the PubMed or GenBank accession number in the document will allow users to access to these databases, and to read the of the literature or the annotation in the DNA database. This report summarizes the present status of this database and available tools.Nucleic Acids Research 02/1999; 27(1):297-300. · 8.28 Impact Factor
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ABSTRACT: The WRKY proteins are a superfamily of transcription factors with up to 100 representatives in Arabidopsis. Family members appear to be involved in the regulation of various physio-logical programs that are unique to plants, including pathogen defense, senescence and trichome development. In spite of the strong conservation of their DNA-binding domain, the overall structures of WRKY proteins are highly divergent and can be categorized into distinct groups, which might reflect their different functions.Trends in Plant Science 06/2000; 5(5):199-206. · 11.81 Impact Factor