Wang X, Watt P M, Louis E J, Borts R H, Hickson I D
Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK.
Nucleic Acids Res. 1996 Dec 1;24(23):4791-7. doi: 10.1093/nar/24.23.4791.
Saccharomyces cerevisiae top2 mutants deficient in topoisomerase II activity are defective in chromosome segregation during both mitotic and meiotic cell divisions. To identify proteins that act in concert with topoisomerase II during chromosome segregation in S.cerevisiae, we have used a two-hybrid cloning approach. We report the isolation of the PAT1 gene (for protein associated with topoisomerase II), which encodes a novel 90 kDa proline- and glutamine-rich protein that interacts with a highly conserved, leucine-rich region of topoisomerase II in vivo. Strains lacking Pat1p exhibit a slow growth rate and a phenotype reminiscent of conditional top2 mutants grown at the semi-permissive temperature; most notably, a reduced fidelity of chromosome segregation during both mitosis and meiosis. These findings indicate that the PAT1 gene is necessary for accurate chromosome transmission during cell division in eukaryotic cells and suggest that the interaction of Pat1p and topoisomerase II is an important component of this function.
酿酒酵母top2突变体中拓扑异构酶II活性缺陷，在有丝分裂和减数分裂细胞分裂过程中的染色体分离均存在缺陷。为了鉴定在酿酒酵母染色体分离过程中与拓扑异构酶II协同作用的蛋白质，我们采用了双杂交克隆方法。我们报道了PAT1基因（与拓扑异构酶II相关的蛋白质）的分离，该基因编码一种新型的90 kDa富含脯氨酸和谷氨酰胺的蛋白质，其在体内与拓扑异构酶II高度保守的富含亮氨酸区域相互作用。缺乏Pat1p的菌株生长速率缓慢，其表型让人联想到在半允许温度下生长的条件性top2突变体；最显著的是，在有丝分裂和减数分裂过程中染色体分离的保真度降低。这些发现表明，PAT1基因对于真核细胞分裂过程中准确的染色体传递是必需的，并表明Pat1p与拓扑异构酶II的相互作用是该功能的重要组成部分。
