Ramalingam Sundhar, Honkanen Peter, Young Lynn, Shimura Tsutomu, Austin John, Steeg Patricia S, Nishizuka Satoshi
Molecular Therapeutics Program, National Cancer Institute, NIH, Bethesda, Maryland, USA.
Cancer Res. 2007 Jul 1;67(13):6247-52. doi: 10.1158/0008-5472.CAN-07-0342.
Mathematical simulations of the p53-Mdm2 feedback loop suggest that both proteins will exhibit impulsive expression characteristics in response to high cellular stress levels. However, little quantitative experimental evaluation has been done, particularly of the phosphorylated forms. To evaluate the mathematical models experimentally, we used lysate microarrays from an isogenic pair of gamma-ray-irradiated cell lysates from HCT116 (p53(+/+) and p53(-/-)). Both p53 and Mdm2 proteins showed expected pulses in the wild type, whereas no pulses were seen in the knockout. Based on experimental observations, we determined model parameters and generated an in silico "knockout," reflecting the experimental data, including phosphorylated proteins.
p53-Mdm2反馈回路的数学模拟表明，在高细胞应激水平下，这两种蛋白质都会表现出脉冲式表达特征。然而，很少有定量实验评估，特别是对磷酸化形式的评估。为了通过实验评估数学模型，我们使用了来自HCT116（p53(+/+)和p53(-/-)）的等基因对γ射线照射细胞裂解物的裂解物微阵列。在野生型中，p53和Mdm2蛋白均显示出预期的脉冲，而在基因敲除型中未观察到脉冲。基于实验观察结果，我们确定了模型参数并生成了一个计算机模拟的“基因敲除”，以反映包括磷酸化蛋白在内的实验数据。
