Localization and anchoring of mRNA in budding yeast
Localization and anchoring of mRNA in budding yeast
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DOI：
10.1016/s0960-9822(99)80260-7
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发表时间：
1999-06-03
期刊：
影响因子：
9.2
通讯作者：
Bloom, K
中科院分区：
文献类型：
--
作者：
Beach, DL;Salmon, ED;Bloom, K
背景：真核细胞将选定的mRNA定位于细胞的一个区域，作为隔离蛋白质的一种手段。3'非翻译区（3' UTR）内的信号通过肌动蛋白和微管细胞骨架系统促进mRNA定位。最近，在酵母酿酒酵母，ASH 1的mRNA，被证明合并成一个离散的颗粒，保持在芽尖。五个基因SHE 1-SHE 5的突变导致颗粒形成和/或ASH 1转录物定位的缺陷。mRNA运输的目的地的因素仍有待于identified.Results：我们已经开发了一个系统，以标记mRNA在活酵母与绿色荧光蛋白（GFP），并遵循mRNA的运动和定位的动力学。组成型表达含有与ASH 1 3 'UTR相邻的噬菌体MS 2外壳蛋白结合位点的ASH 1 mRNA允许我们可视化ASH 1 mRNA与MS 2-外壳蛋白-GFP融合蛋白（一起表示为gRNA（ASH 1））。gRNA（ASH 1）被限制在小到大的出芽细胞中的芽尖，在细胞分离之前迁移到芽颈，然后迅速重新定位到芽生长的初始位点。它还定位于交配期间极化生长的区域。在缺乏参与极性建立和肌动蛋白组织的Bud 6p/Aip 3 p或Bni 1 p/She 5 p的细胞中，gRNA（ASH 1）迁移到芽，但未能留在芽尖。这些研究揭示了mRNA定位的离散运输和锚定步骤。结论：ASH 1 mRNA在整个营养和交配细胞周期中维持在极化生长的位点，Bud 6p/Aip 3 p和Bni 1 p/She 5 p是维持转录本在皮层芽帽的必要条件。
Background: Eukaryotic cells localize selected mRNAs to a region of the cell as a means to sequester proteins. Signals within the 3' untranslated region (3'UTR) facilitate mRNA localization by both actin and microtubule cytoskeletal systems. Recently, an mRNA in the yeast Saccharomyces cerevisiae, ASH1, was shown to coalesce into a discrete particle that is maintained at the bud tip. Mutations in five genes, SHE1 -SHE5, cause defects in particle formation and/or localization of the ASH1 transcript. Factors at the destination of the mRNA transport remain to be identified.Results: We have developed a system to label mRNA in living yeast with green fluorescent protein (GFP) and follow the dynamics of mRNA movement and localization. Constitutively expressing an ASH1 mRNA containing the bacteriophage MS2 coat-protein binding site adjacent to the ASH1 3'UTR allowed us to visualize ASH1 mRNA with an MS2-coat-protein-GFP fusion protein (together denoted gRNA(ASH1)). The gRNA(ASH1) was restricted to the bud tip in small to large budded cells, migrated to the bud neck prior to cell separation and then rapidly relocalized to the incipient site of bud growth. It also localized to regions of polarized growth during mating. In cells lacking Bud6p/Aip3p or Bni1p/She5p, which are involved in polarity establishment and actin organization, gRNA(ASH1) migrated to the bud but failed to remain at the bud tip. These studies reveal discrete transport and anchoring steps in mRNA localization,Conclusions: The ASH1 mRNA was maintained at sites of polarized growth throughout the vegetative and mating cell cycles, Bud6p/Aip3p and Bni1p/She5p are required to maintain the transcript at the cortical bud cap.