The 3′-UTR mediates the cellular localization of an mRNA encoding a short plasma membrane protein
The 3′-UTR mediates the cellular localization of an mRNA encoding a short plasma membrane protein
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DOI：
10.1261/rna.867208
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发表时间：
2008-07-01
期刊：
影响因子：
4.5
通讯作者：
Arava, Yoav
中科院分区：
文献类型：
--
作者：
Loya, Adi;Pnueli, Lilach;Arava, Yoav
一旦信号肽从核糖体出口通道出现，蛋白质共翻译合成到内质网中之前是翻译mRNA的靶向。然而，许多mRNA不太可能被该过程靶向，因为它们编码不含信号肽的蛋白质，或者因为它们太短而不能被信号识别颗粒识别。在此，我们测试了3 '-UTR在编码非常短的酿酒酵母蛋白（Pmp 1）的mRNA的定位中的可能参与。我们通过核糖体密度图、沉降分析、差速离心和荧光原位杂交发现，3 '-UTR对于转录物与膜隔室的缔合是必需的。3 '-UTR与异源开放阅读框的融合赋予它们类似于PMP 1的沉降和细胞定位模式。突变分析显示，在3 '-UTR内的重复的富含UG的序列对于膜结合是重要的。总之，我们的结果揭示了3 '-UTR内的元件在mRNA定位中的重要作用，这可能被标准信号依赖机制所忽略。
Cotranslational synthesis of proteins into the endoplasmic reticulum is preceded by targeting of the translating mRNA once a signal peptide emerges from the ribosome exit tunnel. Many mRNAs, however, are unlikely to be targeted by this process because they encode proteins that do not contain a signal peptide or because they are too short to be recognized by the signal recognition particle. Herein we tested the possible involvement of the 3'-UTR in the localization of an mRNA that encodes a very short Saccharomyces cerevisiae protein (Pmp1). We found by ribosome density mapping, sedimentation analysis, differential centrifugation, and fluorescent in situ hybridization that the 3'-UTR is essential for the association of the transcript with membrane compartments. Fusion of the 3'-UTR to heterologous open reading frames conferred on them a sedimentation and cellular localization pattern resembling that of PMP1. Mutation analysis revealed that a repeating UG-rich sequence within the 3'-UTR is important for membrane association. Taken together, our results reveal an essential role for elements within the 3'-UTR in the localization of an mRNA that is likely to be ignored by the standard signal-dependant mechanism.