C23 interacts with B23, a putative nucleolar-localization-signal-binding protein
C23 interacts with B23, a putative nucleolar-localization-signal-binding protein
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DOI：
10.1111/j.1432-1033.1996.0153n.x
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发表时间：
1996-04-01
期刊：
影响因子：
--
通讯作者：
Busch, H
中科院分区：
文献类型：
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作者：
Li, YP;Busch, RK;Busch, H
人类蛋白质C23（核仁素）是一种主要的核仁蛋白。它与其他蛋白质的相互作用进行了研究与双杂交系统，确定核仁蛋白B23（nucleophosmin）与C23。这两种蛋白质从HeLa细胞核提取物中通过单克隆抗C23或单克隆抗B23共免疫沉淀。利用缺失突变体的结合研究表明，C23和B23的结合涉及特定的基序。除了B23中约46个氨基酸的结合结构域（氨基酸194-239）外，结合还需要C23的氨基酸540-628; C23的该区域是核仁定位所需的。此外，核仁蛋白p120也被发现与B23免疫共沉淀。含有功能性核仁定位信号的p120片段与B23的截短结合结构域结合，C23也是如此。这些结果表明，C23和B23的相互作用可能代表了一种核仁靶向机制，其中B23作为一个核仁定位信号结合蛋白。
The human protein C23 (nucleolin) is a major nucleolar protein. Its interactions with other proteins were studied with the two-hybrid system which identified nucleolar protein B23 (nucleophosmin) as being associated with C23. Both proteins were co-immunoprecipitated from HeLa cell nuclear extract by either monoclonal anti-C23 or monoclonal anti-B23. Binding studies utilizing deletion mutants indicated that the binding of C23 and B23 involves specific motifs. In addition to an approximately 46-amino-acid-binding domain in B23 (amino acids 194-239), amino acids 540-628 of C23 were required for binding; this region of C23 is required for the nucleolar localization. In addition, nucleolar protein p120 was also found to be co-immunoprecipitated with B23. A fragment of p120 containing a functional nucleolar localization signal bound to the truncated binding domain of B23, as did C23. These results suggest that the interaction of C23 and B23 may represent a nucleolar-targeting mechanism in which B23 acts as a nucleolar-localization signal-binding protein.