Yang C L, Zhang S J, Toomey N L, Palmer T N, Lee M Y
Department of Medicine, University of Miami School of Medicine, Florida 33101.
Biochemistry. 1991 Jul 30;30(30):7534-41. doi: 10.1021/bi00244a024.
The levels of DNA polymerase alpha, DNA polymerase delta, and its accessory protein, proliferating cell nuclear antigen (PCNA) were examined in the regenerating rat liver. The levels of DNA polymerase alpha and delta activities in regenerating liver extracts were determined by the use of the DNA polymerase alpha specific inhibitor, BuAdATP [2-(p-n-butylanilino)-9-(2-deoxy-beta-D-ribofuranosyl) adenine 5'-triphosphate], and monoclonal antibodies. These reagents showed that the total DNA polymerase activities increased ca. 4-fold during regeneration and that the fraction of DNA polymerase delta activity at the peak was 40% of the total DNA polymerase activity. Immunoblots and inhibition studies using specific antibodies showed that DNA polymerase delta and epsilon and PCNA were concomitantly induced after partial hepatectomy. The levels of both DNA polymerase delta and epsilon and PCNA reached their maxima at 24-36 h post hepatectomy, i.e., at the same time that in vivo DNA synthesis reached its peak. Partial purification and characterization of DNA polymerases delta and epsilon from the regenerating rat liver were also performed. These observations suggest that the variation of DNA polymerase delta and epsilon and PCNA during liver regeneration is closely related to DNA synthesis and is consistent with their involvement in DNA replication.
在再生的大鼠肝脏中检测了DNA聚合酶α、DNA聚合酶δ及其辅助蛋白增殖细胞核抗原（PCNA）的水平。通过使用DNA聚合酶α特异性抑制剂BuAdATP [2-(对正丁基苯胺基)-9-(2-脱氧-β-D-呋喃核糖基)腺嘌呤5'-三磷酸]和单克隆抗体，测定了再生肝提取物中DNA聚合酶α和δ的活性水平。这些试剂表明，在再生过程中总DNA聚合酶活性增加了约4倍，并且在峰值时DNA聚合酶δ活性的比例占总DNA聚合酶活性的40%。使用特异性抗体的免疫印迹和抑制研究表明，在部分肝切除术后，DNA聚合酶δ和ε以及PCNA被同时诱导。DNA聚合酶δ和ε以及PCNA的水平在肝切除术后24 - 36小时达到最大值，即在体内DNA合成达到峰值的同时。还对再生大鼠肝脏中的DNA聚合酶δ和ε进行了部分纯化和特性分析。这些观察结果表明，肝脏再生过程中DNA聚合酶δ和ε以及PCNA的变化与DNA合成密切相关，并且与它们参与DNA复制一致。
