从中国仓鼠卵巢细胞中分离U3小核仁核糖核蛋白：一种新的55 kDa蛋白与U3小核仁RNA的中央部分结合。

Isolation of U3 snoRNP from CHO cells: a novel 55 kDa protein binds to the central part of U3 snoRNA.

作者信息

Lübben B, Marshallsay C, Rottmann N, Lührmann R

机构信息

Institut für Molekularbiologie und Tumorforschung, Phillipps-Universität Marburg, Germany.

出版信息

Nucleic Acids Res. 1993 Nov 25;21(23):5377-85. doi: 10.1093/nar/21.23.5377.

U3 snoRNP, the most abundant of the small nucleolar ribonucleoprotein particles (snoRNPs), has previously been demonstrated to participate in pre-rRNA maturation. Here we report the purification of U3 snoRNP from CHO cells using anti-m3G-immunoaffinity and mono Q anion-exchange chromatography. Isolated U3 snoRNPs contain three novel proteins, of 15, 50 and 55 kDa respectively. These proteins may represent core U3 snoRNP proteins whose binding mediates the association of other proteins, such as fibrillarin, that are lost during purification. Using a rabbit antiserum raised against the 55 kDa protein, and an in vitro reconstitution assay, we have localised the 55 kDa protein binding site on the U3 snoRNA. Stable binding of the 55 kDa protein requires sequences located between nucleotides 97 and 204 of the human U3 snoRNA, including the evolutionarily conserved B and C sequence motifs.

U3小核仁核糖核蛋白颗粒（snoRNP）是小核仁核糖核蛋白颗粒中含量最丰富的一种，先前已证明其参与前体核糖体RNA（pre-rRNA）的成熟过程。在此，我们报道了使用抗m3G免疫亲和层析和单Q阴离子交换层析从CHO细胞中纯化U3 snoRNP的方法。分离得到的U3 snoRNP包含三种新蛋白质，分子量分别为15 kDa、50 kDa和55 kDa。这些蛋白质可能代表U3 snoRNP的核心蛋白，其结合介导了其他蛋白质（如在纯化过程中丢失的纤维蛋白原）的结合。利用针对55 kDa蛋白质产生的兔抗血清以及体外重组试验，我们已将55 kDa蛋白质的结合位点定位在U3 snoRNA上。55 kDa蛋白质的稳定结合需要人U3 snoRNA核苷酸97至204之间的序列，包括进化上保守的B和C序列基序。