Molecular analysis of the responder satellite DNA in Drosophila melanogaster: DNA bending, nucleosome structure, and Rsp-binding proteins.
Molecular analysis of the responder satellite DNA in Drosophila melanogaster: DNA bending, nucleosome structure, and Rsp-binding proteins.
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果蝇应答卫星 DNA 的分子分析：DNA 弯曲、核小体结构和 Rsp 结合蛋白。
DOI：
10.1093/oxfordjournals.molbev.a040672
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发表时间：
1991
影响因子：
10.7
通讯作者：
Wu,CI
中科院分区：
文献类型：
--
作者：
Doshi,P;Kaushal,S;Benyajati,C;Wu,CI
黑腹果蝇的RSP(Responder)基因座是分离扭曲的靶基因，是一个卫星DNA阵列。这种重复排列为携带它的染色体赋予了一些适应性优势。在这篇文章中，我们报道了这个卫星重复序列的以下三个相关的分子性质：(1)序列定向曲率--在聚丙烯酰胺凝胶上，含有RSP的片段迁移速度比根据其物理尺寸预测的要慢。迁移迟缓的程度与RSP序列在DNA片段中的大小和位置有关，表明RSP DNA是弯曲的。这种弯曲被证明受到一种脱氧核糖核酸结合药物的影响(Hoechst 33258)。(2)核小体结构--与RSP重复相关的核小体具有不寻常的间距模式。它们不是像主体染色质那样以大约190个碱基的间隔隔开，而是以大约240个碱基的间隔分开，大致相当于二聚体RSP重复序列的大小。RSP区域的核小体结构优先被Hoechst 33258破坏，而大块染色质似乎对药物不敏感。(3)RSP-DNA结合蛋白--用蚕蛹核提取物和末端标记的RSP重复序列进行凝胶迁移率分析表明，存在三种不同的DNA-蛋白质复合体。竞争分析表明，这些复合体是RSP序列所特有的，其中两个核蛋白复合体似乎受到Hoechst 33258的影响。观察到的复合体是由体细胞来源的非组蛋白蛋白形成的，可能与RSP的正常功能有关，而不是与生殖系分离扭曲活动有关。
The Responder (Rsp) locus of Drosophila melanogaster, the target locus of segregation distortion, is a satellite DNA array. This repeat array imparts some fitness advantage to the chromosomes bearing it. In this paper, we report the following three related molecular properties of this satellite repeat: (1) Sequence-directed curvature--On a polyacrylamide gel, Rsp-containing fragments migrate slower than would be predicted on the basis of their physical sizes. The extent of migration retardation correlates with the size and position of the Rsp sequence in a DNA fragment, suggesting that Rsp DNA is bent. The bending is shown to be affected by a DNA-binding drug (Hoechst 33258). (2) Nucleosome structure--Nucleosomes associated with Rsp repeats have an unusual spacing pattern. Instead of being spaced at approximately 190-bp intervals as is the bulk chromatin, they are separated at approximately 240-bp intervals, roughly the size of a dimeric Rsp repeat. The nucleosomal structure in the Rsp region is preferentially disrupted by Hoechst 33258, whereas the bulk chromatin appears to be insensitive to the drug. (3) Rsp-DNA binding proteins--Gel mobility-shift assays using nuclear extracts from pupae and end-labeled Rsp repeat demonstrate the presence of three distinct DNA-protein complexes. Competition assays suggest that these complexes are specific to the Rsp sequence, and two of these nucleoprotein complexes seem to be influenced by the presence of Hoechst 33258. The observed complexes are formed by nonhistone proteins of somatic origin and may be related to the normal functions of Rsp, rather than to the germ-line segregation distortion activities.