A role for Drosophila SMC4 in the resolution of sister chromatids in mitosis
A role for Drosophila SMC4 in the resolution of sister chromatids in mitosis
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DOI：
10.1016/s0960-9822(01)00096-3
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发表时间：
2001-03-06
期刊：
影响因子：
9.2
通讯作者：
Sunkel, CE
中科院分区：
文献类型：
--
作者：
Steffensen, S;Coelho, PA;Sunkel, CE
背景资料：在有丝分裂期间基因组的忠实分离需要间期染色质浓缩成明确的染色体。染色体浓缩涉及称为浓缩蛋白的多蛋白复合物，其在前期早期与染色质缔合。到目前为止，尚未进行高等真核细胞中的凝聚素复合物的SMC亚基的遗传分析，因此，不同亚基的有丝分裂染色体形态的形成的详细贡献知之甚少。结果：我们表明，SMC 4凝聚素亚基是由果蝇的必需胶子位点编码。DMSMC 4包含存在于染色体结构维持蛋白家族的其他成员中的所有保守结构域。DMSMC 4在分裂间期位于细胞核和细胞质中，在分裂前期集中在染色质中，在分裂中期和分裂后期定位于轴向染色体核心。在末期的解凝聚过程中，大部分DmSMC 4离开染色体。胶子突变的检查表明，SMC 4所需的染色体凝聚和分离在不同的发育阶段。对突变细胞有丝分裂染色体结构的详细分析表明，尽管纵轴可以正常缩短，但姐妹染色单体的分辨明显中断。这种表型，然后导致严重的染色体分离缺陷，染色体断裂，和apoptosis.Conclusions：我们的研究结果表明，SMC 4是至关重要的决议姐妹染色单体在有丝分裂后期发病之前;（C）2001年爱思唯尔科学有限公司Ail版权所有。
Background: Faithful segregation of the genome during mitosis requires interphase chromatin to be condensed into well-defined chromosomes, Chromosome condensation involves a multiprotein complex known as condensin that associates with chromatin early in prophase. Until now, genetic analysis of SMC subunits of the condensin complex in higher eukaryotic cells has not been performed, and consequently the detailed contribution of different subunits to the formation of mitotic chromosome morphology is poorly understood.Results: We show that the SMC4 subunit of condensin is encoded by the essential gluon locus in Drosophila. DmSMC4 contains all the conserved domains present in other members of the structural-maintenance-of-chromosomes protein family. DmSMC4 is both nuclear and cytoplasmic during interphase, concentrates on chromatin during prophase, and localizes to the axial chromosome core at metaphase and anaphase. During decondensation in telophase, most of the DmSMC4 leaves the chromosomes. An examination of gluon mutations indicates that SMC4 is required for chromosome condensation and segregation during different developmental stages. A detailed analysis of mitotic chromosome structure in mutant cells indicates that although the longitudinal axis can be shortened normally, sister chromatid resolution is strikingly disrupted. This phenotype then leads to severe chromosome segregation defects, chromosome breakage, and apoptosis.Conclusions: Our results demonstrate that SMC4 is critically important for the resolution of sister chromatids during mitosis prior to anaphase onset; (C) 2001 Elsevier Science Ltd. Ail rights reserved.