Roberts J H, Stark P, Smulson M
Proc Natl Acad Sci U S A. 1974 Aug;71(8):3212-6. doi: 10.1073/pnas.71.8.3212.
Evidence is presented to show that ADP-ribosylation of nuclear proteins by poly(ADP-ribose) polymerase enhances template-primer activity of HeLa cell nuclear DNA. We used Escherichia coli DNA polymerase I (EC 2.7.7.7; DNA nucleotidyltransferase) as an exogenous probe of nuclear DNA status. Neither NAD nor free poly(ADP-ribose) acts directly on the bacterial enzyme. The stimulation is specific for formation of ADP-ribosylated proteins and is not a generalized polyanion or nucleotide effect on chromatin. The release of template restriction is proportional to the capacity of a given cell line to synthesize poly(ADP-ribose); both the stimulation and poly(ADP-ribose) formation are coordinately proportional to NAD concentration. Binding studies with DNA polymerase indicate exposure or generation of additional 3'-OH primer sites due to ADP-ribosylation in intact nuclei. With intact cells, there appears a correlation among growth, physiological template restriction, and the above effects of ADP-ribosylation.
有证据表明，聚（ADP - 核糖）聚合酶对核蛋白的ADP - 核糖基化作用可增强HeLa细胞核DNA的模板 - 引物活性。我们使用大肠杆菌DNA聚合酶I（EC 2.7.7.7；DNA核苷酸转移酶）作为细胞核DNA状态的外源性探针。NAD和游离的聚（ADP - 核糖）均不直接作用于该细菌酶。这种刺激对ADP - 核糖基化蛋白的形成具有特异性，并非是对染色质的普遍多聚阴离子或核苷酸效应。模板限制的解除与特定细胞系合成聚（ADP - 核糖）的能力成正比；刺激作用和聚（ADP - 核糖）的形成均与NAD浓度呈协调比例关系。DNA聚合酶的结合研究表明，由于完整细胞核中的ADP - 核糖基化作用，会暴露或产生额外的3'-OH引物位点。在完整细胞中，生长、生理模板限制以及上述ADP - 核糖基化作用之间似乎存在相关性。
