Vlatkovic N, Guerrera S, Li Y, Linn S, Haines D S, Boyd M T
MCP Hahnemann University Cancer Center, Philadelphia, PA 19102, USA.
Nucleic Acids Res. 2000 Sep 15;28(18):3581-6. doi: 10.1093/nar/28.18.3581.
MDM2 is induced by p53 in response to cellular insults such as DNA damage and can have effects upon the cell cycle that are independent or downstream of p53. We used a yeast two-hybrid screen to identify proteins that bind to MDM2 and which therefore might be involved in these effects. We found that MDM2 can bind to the C-terminus of the catalytic subunit of DNA polymerase epsilon (DNA pol epsilon), to a region that is known to be essential in yeast. In an in vitro system we confirmed that MDM2 could bind to the homologous regions of both mouse and human DNA pol epsilon and to full-length human DNA pol epsilon. DNA pol epsilon co-immunoprecipitated with MDM2 from transfected H1299 cells and also from a HeLa cell nuclear extract. We show here that the DNA pol epsilon-interacting domain of MDM2 is located between amino acids 50 and 166. Our studies provide evidence that MDM2 interacts with a region of DNA pol epsilon that plays a critical role in the function of DNA pol epsilon.
MDM2由p53在响应诸如DNA损伤等细胞损伤时诱导产生，并且可对细胞周期产生独立于p53或在p53下游的影响。我们利用酵母双杂交筛选来鉴定与MDM2结合从而可能参与这些影响的蛋白质。我们发现MDM2能够结合DNA聚合酶ε（DNA pol ε）催化亚基的C末端，该区域在酵母中已知是必需的。在体外系统中，我们证实MDM2能够结合小鼠和人DNA pol ε的同源区域以及全长人DNA pol ε。DNA pol ε与转染的H1299细胞以及HeLa细胞核提取物中的MDM2进行共免疫沉淀。我们在此表明MDM2与DNA pol ε的相互作用结构域位于氨基酸50至166之间。我们的研究提供了证据表明MDM2与DNA pol ε的一个在DNA pol ε功能中起关键作用的区域相互作用。
