Fission yeast hrp1, a chromodomain ATPase, is required for proper chromosome segregation and its overexpression interferes with chromatin condensation.
Fission yeast hrp1, a chromodomain ATPase, is required for proper chromosome segregation and its overexpression interferes with chromatin condensation.
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DOI：
10.1093/nar/28.9.2004
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发表时间：
2000-05
影响因子：
14.9
通讯作者：
E. Yoo;Y. H. Jin;Y. Jang;P. Bjerling;M. Tabish;S. Hong;K. Ekwall;Sang Dai Park;Sang Dai Park
中科院分区：
文献类型：
--
作者：
E. Yoo;Y. H. Jin;Y. Jang;P. Bjerling;M. Tabish;S. Hong;K. Ekwall;Sang Dai Park;Sang Dai Park
裂殖酵母Hrp 1是CHD蛋白家族的一员，具有一个染色体结构域、一个Myb样端盒相关的DNA结合结构域和一个SNF 2相关的解旋酶/ATP酶结构域。CHD蛋白被认为是转录中染色质结构修饰所必需的，但CHD蛋白的确切作用尚不清楚。在这里，我们研究的亚细胞定位和生化活性的hrp 1和hrp 1三角洲和hrp 1过表达菌株的表型。荧光显微镜显示Hrp 1蛋白定位于细胞核。我们发现，Hrp 1表现出DNA依赖的ATP酶活性，刺激的单链和双链DNA。Hrp 1的过表达导致细胞生长缓慢，伴随着有缺陷的染色体凝聚在后期，导致“切割”（celluntimelytorn）表型和染色体丢失。hrp 1 Delta突变也引起异常的后期和小染色体丢失表型。电镜观察发现，Hrp 1过表达的细胞中出现了形态异常的核仁。因此，这些结果表明，Hrp 1可能通过利用ATP水解的能量在有丝分裂染色体分离和染色质结构的维持中发挥作用。
Hrp1 of Schizosaccharomyces pombe is a member of the CHD protein family, characterized by a chromodomain, a Myb-like telobox-related DNA-binding domain and a SNF2-related helicase/ATPase domain. CHD proteins are thought to be required for modification of the chromatin structure in transcription, but the exact roles of CHD proteins are not known. Here we examine the sub-cellular localization and biochemical activity of Hrp1 and the phenotypes of hrp1 Delta and Hrp1-overexpressing strains. Fluorescence microscopy revealed that Hrp1 protein is targeted to the nucleus. We found that Hrp1 exhibited DNA-dependent ATPase activity, stimulated by both single- and double-stranded DNA. Overexpression of Hrp1 caused slow cell growth accompanied by defective chromosome condensation in anaphase resulting in a 'cut' (celluntimelytorn) phenotype and chromosome loss. The hrp1 Delta mutation also caused abnormal anaphase and mini-chromosome loss phenotypes. Electron micrographs demonstrated that aberrantly shaped nucleoli appeared in Hrp1-overexpressing cells. Therefore, these results suggest that Hrp1 may play a role in mitotic chromosome segregation and maintenance of chromatin structure by utilizing the energy from ATP hydrolysis.