Functions of fission yeast orp2 in DNA replication and checkpoint control.
Functions of fission yeast orp2 in DNA replication and checkpoint control.
复制标题
裂殖酵母 orp2 在 DNA 复制和检查点控制中的功能。
DOI：
10.1093/genetics/154.2.599
复制
发表时间：
2000
期刊：
影响因子：
3.3
通讯作者：
Leatherwood,J
中科院分区：
文献类型：
--
作者：
Kiely,J;Haase,SB;Russell,P;Leatherwood,J
orp 2是裂殖酵母裂殖酵母的必需基因，与芽殖酵母ORC 2具有22%的同一性。我们分离温度敏感等位基因orp 2使用一种新的质粒洗牌的基础上选择对胸苷激酶。携带温度敏感等位基因orp 2 -2的细胞在限制性温度下不能完成DNA复制，并经历细胞周期停滞。细胞周期阻滞依赖于检查点基因rad 1和rad 3。即使当检查点功能是野生型时，orp 2 -2突变也会导致染色体和质粒的高丢失率。这些表型支持Orp 2是复制起始因子的观点。选择性孢子萌发允许orp 2缺失突变体的分析。这些实验表明，在缺乏orp 2功能的情况下，尽管缺乏DNA复制，细胞仍进行有丝分裂。这表明Orp 2蛋白是检查点机制的一部分，或者更可能是DNA复制起始需要诱导复制检查点信号。
orp2 is an essential gene of the fission yeast Schizosaccharomyces pombe with 22% identity to budding yeast ORC2. We isolated temperature-sensitive alleles of orp2 using a novel plasmid shuffle based on selection against thymidine kinase. Cells bearing the temperature-sensitive allele orp2-2 fail to complete DNA replication at a restrictive temperature and undergo cell cycle arrest. Cell cycle arrest depends on the checkpoint genes rad1 and rad3. Even when checkpoint functions are wild type, the orp2-2 mutation causes high rates of chromosome and plasmid loss. These phenotypes support the idea that Orp2 is a replication initiation factor. Selective spore germination allowed analysis of orp2 deletion mutants. These experiments showed that in the absence of orp2 function, cells proceed into mitosis despite a lack of DNA replication. This suggests either that the Orp2 protein is a part of the checkpoint machinery or more likely that DNA replication initiation is required to induce the replication checkpoint signal.