Maturation-specific translational enhancement mediated by the 5'-UTR of a late pollen transcript
Maturation-specific translational enhancement mediated by the 5'-UTR of a late pollen transcript
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DOI：
10.1046/j.1365-313x.1996.10040613.x
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发表时间：
1996-10-01
期刊：
影响因子：
7.2
通讯作者：
Twell, D
中科院分区：
文献类型：
--
作者：
Bate, N;Spurr, C;Twell, D
番茄的lat52基因编码一种丰富的蛋白，在花粉成熟过程中在花粉粒营养细胞中特异性表达，对花粉管的正常生长至关重要。多个上游顺式调控元件控制着lat52转录的水平和特异性。本研究探讨了5′-非翻译区（5′-UTR）在控制lat52表达中的作用。在瞬时表达试验中，含有lat552′- utr的基因融合构建体在花粉中的表达水平是合成多连锁序列取代lat552′- utr的基因融合构建体的13- 60倍。这种增强被证明是独立于启动子序列，连接的报告基因和3'-UTR。对含有这种基因融合的转基因植物的RNA和蛋白质水平分析表明，在花粉成熟的最后阶段，lat52 5'-UTR以花粉特异性和严格发育调控的方式显著提高了异源转录物的翻译产量。这些结果代表了植物中翻译增强的一个新例子，即翻译产量通过位于5'-UTR内的序列以细胞特异性的方式发育调节。
The tomato lat52 gene encodes an abundant protein specifically expressed in the vegetative cell of the pollen grain during pollen maturation which is essential for normal pollen tube growth. Multiple upstream cis-regulatory elements controlling the level and specificity of lat52 transcription have previously been identified. This research investigated the role of the 5'-untranslated region (5'-UTR) in controlling lat52 expression. In transient expression assays, gene fusion constructs containing the lat52 5'-UTR were expressed in pollen at levels 13- to 60-fold above those in which synthetic polylinker sequences replaced the lat52 5'-UTR. This enhancement was shown to be independent of both the promoter sequences, the linked reporter gene and the 3'-UTR. Analysis of RNA and protein levels in transgenic plants containing such gene fusions demonstrated that the lat52 5'-UTR conferred a dramatically increased translational yield to heterologous transcripts in a pollen-specific and strictly developmentally regulated manner during the final stages of pollen maturation. These results represent a novel example of translational enhancement in plants in that translational yield is regulated developmentally in a cell-specific manner via sequences located within the 5'-UTR.