SARs are cis DNA elements of chromosome dynamics: Synthesis of a SAR repressor protein
SARs are cis DNA elements of chromosome dynamics: Synthesis of a SAR repressor protein
复制标题
DOI：
10.1016/0092-8674(95)90140-x
复制
发表时间：
1995-12-29
期刊：
影响因子：
64.5
通讯作者：
Laemmli, UK
中科院分区：
文献类型：
--
作者：
Strick, R;Laemmli, UK
SAR是确定染色质环碱基的候选DNA元件，并可能作为染色体动力学的顺式元件。SAR包含许多A片段，其改变的DNA结构被协同相互作用的蛋白质如拓扑异构酶II识别。我们构建了多AT钩（MATH）蛋白，并证明它们特异性结合染色质和染色体中SAR的A束簇。它们也是有丝分裂非洲爪蟾提取物中染色体组装的有效抑制剂，证明了SAR在此过程中的重要性。用MATH20（20钩）滴定SAR会阻断染色单体的形状确定，但不会阻断染色质浓缩本身。SAR也是维持染色体形状所必需的。如果在染色单体形成后加入MATH20，染色单体会塌陷，并通过活跃的有丝分裂过程重塑为球形染色单体球。
SARs are candidate DNA elements for defining the bases of chromatin loops and possibly for serving as cis elements of chromosome dynamics. SARs contain numerous A tracts, whose altered DNA structure is recognized by cooperatively interacting proteins such as topoisomerase II. We constructed multi-AT hook (MATH) proteins and demonstrate that they specifically bind the clustered A tracts of SARs in chromatin and chromosomes. They are also potent inhibitors of chromosome assembly in mitotic Xenopus extracts, demonstrating the importance of SARs in this process. Titration of SARs with MATH20 (20 hooks) blocks shape determination of chromatids but not chromatin condensation per se. SARs are also required for shape maintenance of chromosomes. If MATH20 is added after formation of chromatids, they collapse and are reshaped by an active, mitotic process into spherical chromatid balls.