Inner nuclear membrane protein LBR preferentially interacts with DNA secondary structures and nucleosomal linker
Inner nuclear membrane protein LBR preferentially interacts with DNA secondary structures and nucleosomal linker
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DOI：
10.1021/bi992908b
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发表时间：
2000-05-30
期刊：
影响因子：
2.9
通讯作者：
Courvalin, JC
中科院分区：
文献类型：
--
作者：
Duband-Goulet, I;Courvalin, JC
核纤层蛋白B受体（LBR）是核内膜的一种重要蛋白，其核质氨基端结构域参与核内膜与染色质的结合。在这里，我们分析了重组GST蛋白的氨基末端结构域的蛋白质在体外重建的核小体和短的DNA片段的相互作用。数据显示，LBR氨基末端结构域（AT）结合接头DNA，但不与核小体核心相互作用。滴定和竞争研究表明，LBR AT与DNA之间的相互作用是饱和的，具有高亲和力（K-D类似于4 nM），不依赖于DNA序列，并通过DNA弯曲和超螺旋增强。在这方面，LBR氨基末端结构域与核小体的结合类似于组蛋白H1和非组蛋白HMG 1/2，它们都优先与接头DNA结合，并对DNA二级结构具有显著的亲和力。
The lamin B receptor (LBR) is an integral protein of inner nuclear membrane whose nucleoplasmic amino-terminal domain contributes to the attachment of the membrane to chromatin. Here we analyzed the interactions of a recombinant GST protein containing the amino-terminal domain of the protein with in vitro reconstituted nucleosomes and short DNA fragments. Data show that the LBR aminoterminal domain (AT) binds linker DNA but does not interact with the nucleosome core. Titration and competition studies revealed that the interaction between LBR AT and DNA is saturable, of high affinity (K-D similar to 4 nM), independent of DNA sequence, and enhanced by DNA curvature and supercoiling. In this respect, LBR amino-terminal domain binding to nucleosomes is similar to that of histone H1 and non histone proteins HMG1/2 which both bind preferentially to linker DNA and present a significant affinity for DNA secondary structures.