Elfakess Rofa, Dikstein Rivka
Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel.
PLoS One. 2008 Aug 28;3(8):e3094. doi: 10.1371/journal.pone.0003094.
Transcription is controlled by cis regulatory elements, which if localized downstream to the transcriptional start site (TSS), in the 5'UTR, could influence translation as well. However presently there is little evidence for such composite regulatory elements. We have identified by computational analysis an abundant element located downstream to the TSS up to position +30, which controls both transcription and translation. This element has an invariable ATG sequence, which serves as the translation initiation codon in 64% of the genes bearing it. In these genes the initiating AUG is preceded by an extremely short 5'UTR. We show that translation in vitro and in vivo is initiated exclusively from the AUG of this motif, and that the AUG flanking sequences create a strong translation initiation context. This motif is distinguished from the well-known Kozak in its unique ability to direct efficient and accurate translation initiation from mRNAs with a very short 5'UTR. We therefore named it TISU for Translation Initiator of Short 5'UTR. Interestingly, this translation initiation element is also an essential transcription regulatory element of Yin Yang 1. Our characterization of a common transcription and translation element points to a link between mammalian transcription and translation initiation.
转录受顺式调控元件控制，这些元件如果位于转录起始位点（TSS）下游的5'非翻译区（5'UTR），也可能影响翻译。然而，目前几乎没有证据表明存在这种复合调控元件。我们通过计算分析在TSS下游直至+30位置发现了一个丰富的元件，它同时控制转录和翻译。该元件具有一个不变的ATG序列，在携带它的64%的基因中作为翻译起始密码子。在这些基因中，起始AUG之前有一个极短的5'UTR。我们表明，体外和体内翻译均仅从该基序的AUG起始，并且AUG侧翼序列创造了一个强大的翻译起始环境。该基序与著名的科扎克序列（Kozak）不同，其独特之处在于能够从具有极短5'UTR的mRNA中高效准确地指导翻译起始。因此，我们将其命名为TISU，即短5'UTR的翻译起始子。有趣的是，这个翻译起始元件也是阴阳1（Yin Yang 1）的一个重要转录调控元件。我们对一个共同的转录和翻译元件的表征表明了哺乳动物转录和翻译起始之间的联系。
