Molecular mechanism of assembly and control of mammalian replication factories

为了了解哺乳动物DNA复制的分子机制，我重点研究了小鼠DNA聚合酶α。根据对DNA聚合酶α的广泛分析，1)我们从脱氢altenusin衍生物中开发了一种新的有效的哺乳动物DNA聚合酶α抑制剂。利用这种新型抑制剂，我们讨论了NIH3T3细胞中前导链合成和滞后链合成的解偶联导致哺乳动物细胞核中RPA灶的异常。2) DNA聚合酶α突变的温度敏感突变细胞系的鉴定，提出了消除细胞核异常蛋白的新型核蛋白质量控制机制。在这种质量控制机制中涉及HSP90和pa28 γ。3) DNA聚合酶α与pot1的相互作用揭示了DNA聚合酶α内在无序区是染色质结合蛋白的分子结合位点，含有典型的OB-fold含蛋白，如RPA、Mcm10、pot1、CST复合物。

To understand molecular mechanism of mammalian DNA replication, I have focused on mouse DNA polymerase alpha. According to extensive analysis of DNA polymerase alpha,1) we developed a novel potent inhibitor for mammalian DNA polymerase alpha, from derivatives of dehydroaltenusin. Using this novel inhibitor, we discussed that uncoupling of leading strand synthesis and lagging strand synthesis caused aberrant RPA foci in mammalian nucleus in NIH3T3 cells. 2) Characterization of temperature-sensitive mutant cell line which has mutation in DNA polymerase alpha, suggested novel nuclear protein quality control mechanism to eliminate aberrant proteins from nucleus. In this quality control mechanism involves HSP90 and PA28gamma. 3) Interaction between DNA polymerase alpha and pot1 revealed intrinsically disordered region of DNA polymerase alpha serves as molecular binding site for chromatin binding protein which contains typical OB-fold containing proteins such as RPA, Mcm10, pot1, CST complex.