Steitz J A, Berg C, Hendrick J P, La Branche-Chabot H, Metspalu A, Rinke J, Yario T
Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510.
J Cell Biol. 1988 Mar;106(3):545-56. doi: 10.1083/jcb.106.3.545.
A novel 5S RNA-protein (RNP) complex in human and mouse cells has been analyzed using patient autoantibodies. The RNP is small (approximately 7S) and contains most of the nonribosome-associated 5S RNA molecules in HeLa cells. The 5S RNA in the particle is matured at its 3' end, consistent with the results of in vivo pulse-chase experiments which indicate that this RNP represents a later step in 5S biogenesis than a previously described 5S*/La protein complex. The protein moiety of the 5S RNP has been identified as ribosomal protein L5, which is known to be released from ribosomes in a complex with 5S after various treatments of the 60S subunit. Indirect immunofluorescence indicates that the L5/5S complex is concentrated in the nucleolus. L5 may therefore play a role in delivering 5S rRNA to the nucleolus for assembly into ribosomes.
利用患者自身抗体对人和小鼠细胞中的一种新型5S核糖核蛋白（RNP）复合物进行了分析。该RNP体积小（约7S），包含了HeLa细胞中大部分与非核糖体相关的5S RNA分子。颗粒中的5S RNA在其3'端成熟，这与体内脉冲追踪实验的结果一致，该实验表明，与先前描述的5S*/La蛋白复合物相比，这种RNP代表了5S生物合成的后期步骤。5S RNP的蛋白质部分已被鉴定为核糖体蛋白L5，已知在对60S亚基进行各种处理后，它会与5S形成复合物从核糖体中释放出来。间接免疫荧光表明，L5/5S复合物集中在核仁中。因此，L5可能在将5S rRNA输送到核仁以组装成核糖体的过程中发挥作用。
