Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom.
RNA. 2012 Apr;18(4):729-37. doi: 10.1261/rna.026674.111. Epub 2012 Feb 17.
RNA localization is a key mechanism for targeting proteins to particular subcellular domains. Sequences necessary and sufficient for localization have been identified, but little is known about factors that affect its kinetics. Transcripts of gurken and the I factor, a non-LTR retrotransposon, colocalize at the nucleus in the dorso-antero corner of the Drosophila oocyte directed by localization signals, the GLS and ILS. I factor RNA localizes faster than gurken after injection into oocytes, due to a difference in the intrinsic localization ability of the GLS and ILS. The kinetics of localization of RNA containing the ILS are enhanced by the presence of a stem-loop, the A loop. This acts as an RNA:RNA interaction element in vivo and in vitro, and stimulates localization of RNA containing other localization signals. RNA:RNA interaction may be a general mechanism for modulating RNA localization and could allow an mRNA that lacks a localization signal to hitchhike on another RNA that has one.
RNA 定位是将蛋白质靶向特定亚细胞区域的关键机制。已经确定了定位所必需和足够的序列，但对于影响其动力学的因素知之甚少。由定位信号指导，gurken 和非 LTR 逆转录转座子 I 因子的转录本在果蝇卵母细胞的背-前角的核中共定位。由于 GLS 和 ILS 的内在定位能力不同，注射到卵母细胞中的 I 因子 RNA 的定位速度快于 gurken。含有 ILS 的 RNA 的定位动力学通过茎环，即 A 环增强。该环在体内和体外充当 RNA:RNA 相互作用元件，并刺激含有其他定位信号的 RNA 的定位。RNA:RNA 相互作用可能是调节 RNA 定位的一般机制，并允许缺乏定位信号的 mRNA 搭乘具有定位信号的另一个 RNA。
