Li X, Coffino P
Department of Microbiology and Immunology, University of California, San Francisco, 94143, USA.
J Biol Chem. 1996 Feb 23;271(8):4447-51. doi: 10.1074/jbc.271.8.4447.
Degradation provides one means for controlling the cellular level of the p53 tumor suppressor. Here we have determined a structural element of p53 required for degradation. To create a substrate amenable to in vitro analysis of proteolysis, we appended to p53 the N terminus of antizyme, a protein that binds to and induces degradation of mammalian ornithine decarboxylase (ODC). We found using deletion analysis that an element within amino acids 100-150 is required for degradation of the fusion protein. A monoclonal antibody (PAb246) that binds close to this region prevents the degradation induced by human papillomavirus 16 E6 protein. Furthermore, we found that amino acids 100-150 of p53 can function as an independent domain to induce Trypanosoma brucei ODC, a stable protein, to be degraded in vivo or, by cooperating with an antizyme binding domain of ODC, to confer polyamine-dependent regulation.
降解是控制p53肿瘤抑制因子细胞水平的一种方式。在此，我们确定了p53降解所需的一个结构元件。为了创建一个适合蛋白水解体外分析的底物，我们将抗酶的N端附加到p53上，抗酶是一种与哺乳动物鸟氨酸脱羧酶（ODC）结合并诱导其降解的蛋白质。我们通过缺失分析发现，融合蛋白降解需要100 - 150位氨基酸内的一个元件。一种结合在该区域附近的单克隆抗体（PAb246）可阻止人乳头瘤病毒16 E6蛋白诱导的降解。此外，我们发现p53的100 - 150位氨基酸可作为一个独立结构域，在体内诱导稳定蛋白布氏锥虫ODC降解，或者通过与ODC的抗酶结合结构域协同作用，赋予多胺依赖性调控。
