Roos G, Jiang Y, Landberg G, Nielsen N H, Zhang P, Lee M Y
Department of Pathology, Umeå University, Umeå, S-90187, Sweden.
Exp Cell Res. 1996 Jul 10;226(1):208-13. doi: 10.1006/excr.1996.0220.
Proliferating cell nuclear antigen (PCNA) is an essential component for the normal processive DNA synthesis by DNA polymerase delta and is also required for DNA excision repair. Human PCNA autoantisera has been shown to inhibit the function of PCNA in vitro, in contrast to induced antibodies. A monoclonal IgG2 PCNA antibody, 74B1, that effectively inhibited DNA replication in vitro was identified. The inhibitory effect was dose dependent and using synthetic overlapping peptides of PCNA the 74B1 epitope was mapped to aa 121-135, a region of the PCNA protein containing the interdomain connector implicated in intermolecular interactions. Interestingly, a neighboring and partly overlapping peptide, aa 111-125, contains an immunodominant region recognized by a number of monoclonal PCNA antibodies with no inhibitory effect on DNA synthesis. The 74B1 antibody is a potentially useful antibody in future studies of PCNA and its interaction in complexes associated with cell cycle progress, DNA replication, and DNA repair.
增殖细胞核抗原（PCNA）是DNA聚合酶δ进行正常连续DNA合成过程中的重要组成部分，也是DNA切除修复所必需的。与诱导抗体不同，人PCNA自身抗血清已被证明在体外可抑制PCNA的功能。一种单克隆IgG2 PCNA抗体74B1被鉴定出来，它在体外能有效抑制DNA复制。这种抑制作用呈剂量依赖性，利用PCNA的合成重叠肽，74B1表位被定位到氨基酸121 - 135，这是PCNA蛋白中包含与分子间相互作用有关的结构域间连接区的一个区域。有趣的是，一个相邻且部分重叠的肽段，氨基酸111 - 125，包含一个免疫显性区域，被许多对DNA合成无抑制作用的单克隆PCNA抗体识别。74B1抗体在未来PCNA及其在与细胞周期进程、DNA复制和DNA修复相关复合物中的相互作用的研究中可能是一种有用的抗体。
