Long R M, Singer R H, Meng X, Gonzalez I, Nasmyth K, Jansen R P
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
Science. 1997 Jul 18;277(5324):383-7. doi: 10.1126/science.277.5324.383.
Cell divisions that produce progeny differing in their patterns of gene expression are key to the development of multicellular organisms. In the budding yeast Saccharomyces cerevisiae, mother cells but not daughter cells can switch mating type because they selectively express the HO endonuclease gene. This asymmetry is due to the preferential accumulation of an unstable transcriptional repressor protein, Ash1p, in daughter cell nuclei. Here it is shown that ASH1 messenger RNA (mRNA) preferentially accumulates in daughter cells by a process that is dependent on actin and myosin. A cis-acting element in the 3'-untranslated region of ASH1 mRNA is sufficient to localize a chimeric RNA to daughter cells. These results suggest that localization of mRNA may have been an early property of the eukaryotic lineage.
产生基因表达模式不同的子代细胞的细胞分裂是多细胞生物发育的关键。在出芽酵母酿酒酵母中，母细胞而非子细胞能够转换交配型，因为它们选择性地表达HO核酸内切酶基因。这种不对称性是由于一种不稳定的转录抑制蛋白Ash1p在子细胞核中优先积累所致。本文表明，ASH1信使核糖核酸（mRNA）通过一个依赖于肌动蛋白和肌球蛋白的过程优先在子细胞中积累。ASH1 mRNA 3'非翻译区中的一个顺式作用元件足以将嵌合RNA定位于子细胞。这些结果表明，mRNA的定位可能是真核生物谱系的一个早期特性。
