Activation of the promoters of arabidopsis genes for the branched-chain α-keto acid dehydrogenase complex in transgenic tobacco BY-2 cells under sugar starvation

被引：24

作者：

Fujiki, Y ^{[1
]}

Ito, M ^{[1
]}

Itoh, T ^{[1
]}

Nishida, I ^{[1
]}

Watanabe, A ^{[1
]}

机构：

[1] Univ Tokyo, Grad Sch Sci, Dept Biol Sci, Tokyo 1130033, Japan

来源：

PLANT AND CELL PHYSIOLOGY | 2002年 / 43卷 / 03期

基金：

日本学术振兴会;

关键词：

branched-chain alpha-keto acid dehydrogenase promoter; protein kinase; protein phosphatase; sugar starvation;

D O I：

10.1093/pcp/pcf032

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

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 a-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 a-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.

引用

页码：275 / 280

页数：6

共 33 条

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