Partitioning of the 2-microm circle plasmid of Saccharomyces cerevisiae. Functional coordination with chromosome segregation and plasmid-encoded rep protein distribution.
Partitioning of the 2-microm circle plasmid of Saccharomyces cerevisiae. Functional coordination with chromosome segregation and plasmid-encoded rep protein distribution.
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DOI：
10.1083/jcb.149.3.553
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发表时间：
2000-05-01
期刊：
影响因子：
--
通讯作者：
Jayaram M
中科院分区：
文献类型：
--
作者：
Velmurugan S;Yang XM;Chan CS;Dobson M;Jayaram M
酿酒酵母2-μm质粒在细胞分裂时的有效分割依赖于两个编码蛋白质(Rep1p和Rep2p)以及顺式作用基因Rep3(STb)。此外，宿主编码的因素也可能对质粒分离起作用。在酵母活细胞中直接观察到2-μm衍生的质粒表明，多个质粒拷贝位于细胞核中，主要以具有特征形状的簇状形式存在。与单标记染色体或酵母着丝粒质粒的比较表明，在酵母细胞周期中，2-μm质粒和染色体的分离动力学非常相似。免疫荧光分析表明，该质粒与Rep1和Rep2蛋白共存于酵母细胞核内。此外，Rep蛋白(因此也是质粒)倾向于集中在酵母有丝分裂纺锤体的两极附近。纺锤体的解聚导致Rep蛋白在细胞核中的部分分散，伴随着质粒分子之间的结合松散。在转移到不允许的温度下的Ipl1-2酵母菌株中，染色体和质粒几乎总是错误分离。我们的结果表明，在DNA复制后，质粒以特定的DNA-蛋白质聚集体的形式分布到子代细胞中。他们进一步指出，质粒分割机制至少可以利用染色体分离所需的细胞机制的一些组件。
The efficient partitioning of the 2-μm plasmid of Saccharomyces cerevisiae at cell division is dependent on two plasmid-encoded proteins (Rep1p and Rep2p), together with the cis-acting locus REP3 (STB). In addition, host encoded factors are likely to contribute to plasmid segregation. Direct observation of a 2-μm–derived plasmid in live yeast cells indicates that the multiple plasmid copies are located in the nucleus, predominantly in clusters with characteristic shapes. Comparison to a single-tagged chromosome or to a yeast centromeric plasmid shows that the segregation kinetics of the 2-μm plasmid and the chromosome are quite similar during the yeast cell cycle. Immunofluorescence analysis reveals that the plasmid is colocalized with the Rep1 and Rep2 proteins within the yeast nucleus. Furthermore, the Rep proteins (and therefore the plasmid) tend to concentrate near the poles of the yeast mitotic spindle. Depolymerization of the spindle results in partial dispersion of the Rep proteins in the nucleus concomitant with a loosening in the association between plasmid molecules. In an ipl1-2 yeast strain, shifted to the nonpermissive temperature, the chromosomes and plasmid almost always missegregate in tandem. Our results suggest that, after DNA replication, plasmid distribution to the daughter cells occurs in the form of specific DNA-protein aggregates. They further indicate that the plasmid partitioning mechanism may exploit at least some of the components of the cellular machinery required for chromosomal segregation.
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影响因子：
64.5
作者：
HUBERMAN, JA;SPOTILA, LD;DAVIS, LR
通讯作者：
DAVIS, LR
影响因子：
11.4
作者：
MURRAY, JAH;SCARPA, M;CESARENI, G
通讯作者：
CESARENI, G
DOI：
10.1007/bf00338076
发表时间：
1986-01-01
期刊：
MOLECULAR AND GENERAL GENETICS
影响因子：
--
作者：
MEAD, DJ;GARDNER, DCJ;OLIVER, SG
通讯作者：
OLIVER, SG
DOI：
10.1083/jcb.145.7.1381
发表时间：
1999-06-28
期刊：
The Journal of cell biology
影响因子：
--
作者：
Kim JH;Kang JS;Chan CS
通讯作者：
Chan CS
影响因子：
64.5
作者：
Hirano, T;Kobayashi, R;Hirano, M
通讯作者：
Hirano, M