Fu Dragony, Collins Kathleen
Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA.
Genes Dev. 2006 Mar 1;20(5):531-6. doi: 10.1101/gad.1390306. Epub 2006 Feb 15.
Cajal bodies are nuclear structures that host RNA modification and assembly reactions. Some RNAs transit Cajal bodies, while others must concentrate in Cajal bodies to function. Here we report that at least a subfraction of human telomerase RNA and individual resident Cajal body RNAs is associated with Sm proteins. Surprisingly, of seven Sm proteins assembled into a heteroheptameric ring, only a subset copurifies telomerase and Cajal body ribonucleoproteins. We show that a Cajal body RNA localization motif determines this specificity. These discoveries expand the cellular repertoire of Sm protein assemblies and their involvement in ribonucleoprotein localization and function.
卡哈尔体是进行RNA修饰和组装反应的核结构。一些RNA会穿过卡哈尔体,而另一些则必须聚集在卡哈尔体中才能发挥功能。在此我们报告,人类端粒酶RNA的至少一部分亚组分以及个别常驻卡哈尔体RNA与Sm蛋白相关联。令人惊讶的是,在组装成异源七聚体环的七种Sm蛋白中,只有一部分与端粒酶和卡哈尔体核糖核蛋白共同纯化。我们表明,卡哈尔体RNA定位基序决定了这种特异性。这些发现扩展了Sm蛋白组装体的细胞种类及其在核糖核蛋白定位和功能中的作用。