Gonsalvez Graydon B, Urbinati Carl R, Long Roy M
Department of Genetics, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA.
Biol Cell. 2005 Jan;97(1):75-86. doi: 10.1042/BC20040066.
RNA localization is a widely utilized strategy employed by cells to spatially restrict protein function. In Saccharomyces cerevisiae asymmetric sorting of mRNA to the bud has been reported for at least 24 mRNAs. The mechanism by which the mRNAs are trafficked to the bud, illustrated by ASH1 mRNA, involves recognition of cis-acting localization elements present in the mRNA by the RNA-binding protein, She2p. The She2p/mRNA complex subsequently associates with the myosin motor protein, Myo4p, through an adapter, She3p. This ribonucleoprotein complex is transported to the distal tip of the bud along polarized actin cables. While the mechanism by which ASH1 mRNA is anchored at the bud tip is unknown, current data point to a role for translation in this process, and the rate of translation of Ash1p during the transport phase is regulated by the cis-acting localization elements. Subcellular sorting of mRNA in yeast is not limited to the bud; certain mRNAs corresponding to nuclear-encoded mitochondrial proteins are specifically sorted to the proximity of mitochondria. Analogous to ASH1 mRNA localization, mitochondrial sorting requires cis-acting elements present in the mRNA, though trans-acting factors involved with this process remain to be identified. This review aims to discuss mechanistic details of mRNA localization in S. cerevisiae.
RNA定位是细胞广泛采用的一种策略，用于在空间上限制蛋白质的功能。在酿酒酵母中，至少有24种mRNA被报道会不对称地分选到芽中。以ASH1 mRNA为例，mRNA被运输到芽的机制涉及RNA结合蛋白She2p对mRNA中存在的顺式作用定位元件的识别。随后，She2p/mRNA复合物通过衔接蛋白She3p与肌球蛋白运动蛋白Myo4p结合。这种核糖核蛋白复合物沿着极化的肌动蛋白电缆被运输到芽的远端。虽然ASH1 mRNA锚定在芽尖的机制尚不清楚，但目前的数据表明翻译在这个过程中起作用，并且在运输阶段Ash1p的翻译速率受顺式作用定位元件的调节。酵母中mRNA的亚细胞分选并不局限于芽；某些对应于核编码线粒体蛋白的mRNA会被特异性地分选到线粒体附近。与ASH1 mRNA定位类似，线粒体分选需要mRNA中存在顺式作用元件，尽管参与这个过程的反式作用因子仍有待确定。这篇综述旨在讨论酿酒酵母中mRNA定位的机制细节。
