D'Ambrosio Claudio, Schmidt Christine Katrin, Katou Yuki, Kelly Gavin, Itoh Takehiko, Shirahige Katsuhiko, Uhlmann Frank
Chromosome Segregation Laboratory, Cancer Research UK London Research Institute, London, UK.
Genes Dev. 2008 Aug 15;22(16):2215-27. doi: 10.1101/gad.1675708.
Eukaryotic chromosomes reach their stable rod-shaped appearance in mitosis in a reaction dependent on the evolutionarily conserved condensin complex. Little is known about how and where condensin associates with chromosomes. Here, we analyze condensin binding to budding yeast chromosomes using high-resolution oligonucleotide tiling arrays. Condensin-binding sites coincide with those of the loading factor Scc2/4 of the related cohesin complex. The sites map to tRNA and other genes bound by the RNA polymerase III transcription factor TFIIIC, and ribosomal protein and SNR genes. An ectopic B-box element, recognized by TFIIIC, constitutes a minimal condensin-binding site, and TFIIIC and the Scc2/4 complex promote functional condensin association with chromosomes. A similar pattern of condensin binding is conserved along fission yeast chromosomes. This reveals that TFIIIC-binding sites, including tRNA genes, constitute a hitherto unknown chromosomal feature with important implications for chromosome architecture during both interphase and mitosis.
真核生物染色体在有丝分裂中呈现出稳定的杆状形态，这一过程依赖于进化上保守的凝聚素复合体。关于凝聚素如何以及在何处与染色体结合，我们所知甚少。在此，我们使用高分辨率寡核苷酸平铺阵列分析凝聚素与芽殖酵母染色体的结合情况。凝聚素结合位点与相关黏连蛋白复合体的装载因子Scc2/4的结合位点一致。这些位点定位于RNA聚合酶III转录因子TFIIIC所结合的tRNA和其他基因，以及核糖体蛋白和SNR基因。TFIIIC识别的异位B盒元件构成了最小的凝聚素结合位点，并且TFIIIC和Scc2/4复合体促进凝聚素与染色体的功能性结合。沿着裂殖酵母染色体，凝聚素结合的类似模式是保守的。这揭示了包括tRNA基因在内的TFIIIC结合位点构成了一种迄今未知的染色体特征，对间期和有丝分裂期间的染色体结构具有重要意义。
