Physical interaction of apoptosis-inducing factor with DNA and RNA
Physical interaction of apoptosis-inducing factor with DNA and RNA
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DOI：
10.1038/sj.onc.1209206
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发表时间：
2006-03-01
期刊：
影响因子：
8
通讯作者：
Kroemer, G
中科院分区：
文献类型：
--
作者：
Vahsen, N;Candé, C;Kroemer, G
细胞凋亡诱导因子 (AIF) 是一种线粒体黄素蛋白，在细胞凋亡诱导后易位至细胞核，并通过 AIF 表面聚集的正电荷与 DNA 相互作用。在这里，我们表明，通过质谱法测定，AIF 相互作用组包含一大组核糖核蛋白，它们显然通过 RNA 部分与 AIF 结合。然而，AIF 在体外和体内均缺乏任何可检测的 RNAse 活性。重组 AIF 可以直接结合 DNA 以及 RNA。这种结合可以通过电子显微镜观察到，表明 AIF 可以浓缩 DNA，显示出与单链 DNA 的结合优先于双链 DNA。 AIF 还在体外结合并聚集单链和结构化 RNA。单链多聚 A、多聚 G 和多聚 C，以及双链 A/T 和 G/C RNA 以相似的效率与 DNA 竞争 AIF 结合，从而证实了计算机计算的分子模型，其中 AIF 内的结合位点对于不同的核酸种类是相同的，没有明确的序列特异性。在 AIF 的优选电子供体和受体中，烟碱腺嘌呤二核苷酸磷酸 (NADP) 在增强高级 AIF/DNA 和 AIF/RNA 复合物的生成方面特别有效。总而言之，这些数据支持一个模型，其中 AIF 的直接相互作用有助于压缩凋亡细胞内的核酸。
Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein, which upon apoptosis induction translocates to the nucleus where it interacts with DNA by virtue of positive charges clustered on the AIF surface. Here we show that the AIF interactome, as determined by mass spectroscopy, contains a large panel of ribonucleoproteins, which apparently bind to AIF through the RNA moiety. However, AIF is devoid of any detectable RNAse activity both in vitro and in vivo. Recombinant AIF can directly bind to DNA as well as to RNA. This binding can be visualized by electron microscopy, revealing that AIF can condense DNA, showing a preferential binding to single-stranded over double-stranded DNA. AIF also binds and aggregates single-stranded and structured RNA in vitro. Single-stranded poly A, poly G and poly C, as well double-stranded A/T and G/C RNA competed with DNA for AIF binding with a similar efficiency, thus corroborating a computer-calculated molecular model in which the binding site within AIF is the same for distinct nucleic acid species, without a clear sequence specificity. Among the preferred electron donors and acceptors of AIF, nicotine adenine dinucleotide phosphate (NADP) was particularly efficient in enhancing the generation of higher-order AIF/DNA and AIF/RNA complexes. Altogether, these data support a model in which a direct interaction of AIF contributes to the compaction of nucleic acids within apoptotic cells.