RRC ID 2007
Author Fujiki Y, Ito M, Itoh T, Nishida I, Watanabe A.
Title Activation of the promoters of Arabidopsis genes for the branched-chain alpha-keto acid dehydrogenase complex in transgenic tobacco BY-2 cells under sugar starvation.
Journal Plant Cell Physiol
Abstract Sugar starvation exerted by sub-10 mM levels of sucrose on Arabidopsis T87 suspension-cultured cells triggered marked accumulation of the transcripts of genes for E1beta and E2 subunit of the branched-chain alpha-keto acid dehydrogenase complex. Similar levels of sugar starvation increased the luciferase activity in transgenic tobacco BY-2 lines expressing the Arabidopsis E1beta- or E2-promoter-luciferase fusion gene. These results indicate that sugar levels tightly regulate the E1beta and E2 promoter activity in the heterologous plant system. We further showed in the transgenic tobacco BY-2 lines that sugar-starvation-induced activation of the E1beta and E2 promoters was prevented by K-252a, an inhibitor of Ser/Thr protein kinase, and was enhanced by okadaic acid, an inhibitor of protein phosphatases. By contrast, the cauliflower mosaic virus 35S promoter activity in sugar-starved BY-2 cells was not significantly affected by K-252a and only slightly enhanced by okadaic acid. Taken together, we propose that transcriptional activation of genes for the branched-chain alpha-keto acid dehydrogenase complex and its modulation by specific protein kinases/phosphatases are of critical importance in branched-chain amino acid catabolism in plant cells under sugar starvation.
Volume 43(3)
Pages 275-80
Published 2002-3-1
DOI 10.1093/pcp/pcf032
PMID 11917081
MeSH 3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide) Acetyltransferases / genetics Arabidopsis / enzymology Arabidopsis / genetics* Carbazoles / pharmacology Cell Line Cells, Cultured Dihydrolipoamide Dehydrogenase / genetics Dihydrolipoyllysine-Residue Acetyltransferase Dimethyl Sulfoxide / pharmacology Gene Expression Regulation, Enzymologic / drug effects Gene Expression Regulation, Plant / drug effects Indole Alkaloids Ketone Oxidoreductases / genetics* Luciferases / genetics Luciferases / metabolism Molecular Sequence Data Multienzyme Complexes / genetics* Okadaic Acid / pharmacology Plants, Genetically Modified Promoter Regions, Genetic / genetics* Protein Kinase C / antagonists & inhibitors Pyruvate Dehydrogenase Complex / genetics Sucrose / pharmacology* Tobacco / cytology
IF 4.062
Times Cited 21
Arabidopsis / Cultured plant cells, genes rpc00008