The 3′ untranslated region of a rice α-amylase gene functions as a sugar-dependent mRNA stability determinant
The 3′ untranslated region of a rice α-amylase gene functions as a sugar-dependent mRNA stability determinant
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DOI：
10.1073/pnas.95.11.6543
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发表时间：
1998-05-26
影响因子：
11.1
通讯作者：
Yu, SM
中科院分区：
文献类型：
--
作者：
Chan, MT;Yu, SM
在植物中，糖反馈调节提供了一种控制组织和器官间碳水化合物分配和利用的机制。糖抑制水稻α -淀粉酶基因表达为研究糖反馈调控机制提供了理想的模型。我们之前已经证明，糖抑制水稻悬浮细胞中α -淀粉酶基因表达涉及转录率和mRNA稳定性的控制。-淀粉酶mRNA在缺糖细胞中比在提供蔗糖的细胞中更稳定。为了阐明糖依赖性mRNA转换的机制，我们通过对转化水稻悬浮细胞的功能分析，研究了α Amy3 3'非翻译区（UTR）对mRNA稳定性的影响。我们发现整个α Amy3 3' UTR和它的两个亚结构域可以独立地介导报告mRNA积累的糖依赖性抑制。对报告基因mRNA半衰期的分析表明，整个α Amy3 3' UTR和两个亚结构域各自在mRNA的转换中作为糖依赖的不稳定决定因素发挥作用。核运行转录分析进一步证实，α Amy3 3' UTR和两个亚结构域不影响启动子的转录率。鉴定α -淀粉酶mRNA中决定差异稳定性的序列元件对研究糖依赖性mRNA衰变机制具有重要意义。
In plants, sugar feedback regulation provides a mechanism for control of carbohydrate allocation and utilization among tissues and organs. The sugar repression of alpha-amylase gene expression in rice provides an ideal model for studying the mechanism of sugar feedback regulation. We have shown previously that sugar repression of alpha-amylase gene expression in rice suspension cells involves control of both transcription rate and mRNA stability. The alpha-amylase mRNA is significantly more stable in sucrose-starved cells than in sucrose-provided cells. To elucidate the mechanism of sugar-dependent mRNA turnover, we have examined the effect of alpha Amy3 3' untranslated region (UTR) on mRNA stability by functional analyses in transformed rice suspension cells. We found that the entire alpha Amy3 3' UTR and two of its subdomains can independently mediate sugar-dependent repression of reporter mRNA accumulation. Analysis of reporter mRNA half-lives demonstrated that the entire alpha Amy3 3' UTR and the two subdomains each functioned as a sugar-dependent destabilizing determinant in the turnover of mRNA. Nuclear run-on transcription analysis further confirmed that the alpha Amy3 3' UTR and the two subdomains did not affect the transcription rate of promoter. The identification of sequence elements in the alpha-amylase mRNA that dictate the differential stability has very important implications for the study of sugar-dependent mRNA decay mechanisms.