STRUCTURAL REQUIREMENTS OF 5S RIBOSOMAL-RNA FOR NUCLEAR TRANSPORT, 7S RIBONUCLEOPROTEIN PARTICLE ASSEMBLY, AND 60S RIBOSOMAL-SUBUNIT ASSEMBLY IN XENOPUS-OOCYTES
STRUCTURAL REQUIREMENTS OF 5S RIBOSOMAL-RNA FOR NUCLEAR TRANSPORT, 7S RIBONUCLEOPROTEIN PARTICLE ASSEMBLY, AND 60S RIBOSOMAL-SUBUNIT ASSEMBLY IN XENOPUS-OOCYTES
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DOI：
10.1128/mcb.13.11.6819
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发表时间：
1993-11-01
影响因子：
5.3
通讯作者：
LEMAIRE, M
中科院分区：
文献类型：
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作者：
ALLISON, LA;NORTH, MT;LEMAIRE, M
通过分析卵母细胞型5S rRNA和31种不同的体外产生的突变体转录物显微注射到非洲爪蟾卵母细胞的细胞质中后的行为，研究了5S rRNA的核转运和RNA-蛋白质相互作用的结构要求。实验表明，5S rRNA的序列和二级和/或三级结构的要求，核运输，在细胞质中储存为7S核糖核蛋白颗粒，并组装成60 S核糖体亚基是复杂的和不相同的。环A，C和E，螺旋II和V，以及5S rRNA中央结构域中的凸起和铰链核苷酸的元件携带这些功能活动的基本信息。显微注射的SS rRNA组装成60 S核糖体亚基显示发生在细胞核中;因此，亚基组装的第一个要求是核靶向。ATP耗竭、小麦胚芽凝集素和低温对5S rRNA核输入的抑制作用表明，5S rRNA通过核孔复合物穿过核膜的途径类似于嗜核蛋白所使用的途径。
Structural requirements of 5S rRNA for nuclear transport and RNA-protein interactions have been studied by analyzing the behavior of oocyte-type 5S rRNA and of 31 different in vitro-generated mutant transcripts after microinjection into the cytoplasm of Xenopus oocytes. Experiments reveal that the sequence and secondary and/or tertiary structure requirements of 5S rRNA for nuclear transport, storage in the cytoplasm as 7S ribonucleoprotein particles, and assembly into 60S ribosomal subunits are complex and nonidentical. Elements of loops A, C, and E, helices II and V, and bulged and hinge nucleotides in the central domain of 5S rRNA carry the essential information for these functional activities. Assembly of microinjected SS rRNA into 60S ribosomal subunits was shown to occur in the nucleus; thus, the first requirement for subunit assembly is nuclear targeting. The inhibitory effects of ATP depletion, wheat germ agglutinin, and chilling on the nuclear import of 5S rRNA indicate that it crosses the nuclear envelope through the nuclear pore complex by a pathway similar to that used by karyophilic proteins.