Replication of nuclear and mitochondrial DNA in X-ray-damaged cells: evidence for a nuclear-specific mechanism that down-regulates replication.
Replication of nuclear and mitochondrial DNA in X-ray-damaged cells: evidence for a nuclear-specific mechanism that down-regulates replication.
复制标题
X 射线损伤细胞中核和线粒体 DNA 的复制：下调复制的核特异性机制的证据。
作者：
J. Cleaver
X射线抑制DNA复制的机制已经在人类细胞中三个不同的DNA分子群体中进行了研究：(a)大的染色体DNA， (b)每个细胞50-100个10.3 kb的核外泌质粒群体，以及(c)每个细胞约500个16 kb的细胞质线粒体DNA分子群体。X射线对核染色体和质粒DNA的复制有抑制作用，但对线粒体DNA无抑制作用。因此，电离辐射抑制DNA复制的机制必须是核特异性的，不太可能涉及可扩散的低分子量物质。由于线粒体DNA作为独立的16kb圆形分子存在于细胞中，并且像预期的小靶标一样对辐射作出反应，因此核质粒的复制受到大靶标的调节。当前的DNA复制模型涉及DNA通过由聚合酶、解旋酶和相关复制酶组成的复制中心的运动，这些复制中心附着在基质上。线粒体DNA和核质粒DNA对X射线反应的差异可以解释，如果核质粒与染色体DNA紧密相关并附着在基质上，并且协调复制。
The mechanism by which X rays inhibit DNA replication has been investigated in three distinct populations of DNA molecules in human cells: (a) large chromosomal DNA, (b) a population of 50-100 10.3-kb nuclear episomal plasmids per cell, and (c) a population of about 500 16-kb cytoplasmic mitochondrial DNA molecules per cell. DNA replication was inhibited by X rays in nuclear chromosomal and plasmid DNA, but not in mitochondrial DNA. The mechanism by which ionizing radiation inhibits DNA replication must therefore be nuclear-specific and is unlikely to involve diffusible low-molecular-weight substances. Since mitochondrial DNA exists in the cell as independent 16-kb circular molecules and responds to radiation as would be expected for small targets, the implication for nuclear plasmids is that their replication is regulated by a large target. A current model for DNA replication involves the movement of DNA through replication centers made up of polymerases, helicases, and associated replication enzymes that are attached to a matrix. The difference in the response to X rays between mitochondrial DNA and nuclear plasmid DNA can be explained if nuclear plasmids are tightly associated with chromosomal DNA and attached to the matrix, and are coordinately replicated.
影响因子：
9.8
作者：
Leon N. Kapp;Robert B. Painter;Yu Lc;N. vanLoon;Richard Cw rd;Michael R. James;David Cox;J. Murnane
通讯作者：
Leon N. Kapp;Robert B. Painter;Yu Lc;N. vanLoon;Richard Cw rd;Michael R. James;David Cox;J. Murnane
影响因子：
--
作者：
D. Tapper;R. A. Etten;David A. Clayton
通讯作者：
D. Tapper;R. A. Etten;David A. Clayton
暴露于亚硝脲链脲佐菌素后，RINr 38 细胞线粒体 DNA 内碱不稳定位点的修复。
DOI：
--
发表时间：
1991
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Pettepher,CC;LeDoux,SP;Bohr,VA;Wilson,GL
通讯作者：
Wilson,GL