摘要
作为抑癌蛋白,p53参与了细胞内多种信号转导过程,并在细胞周期调控、细胞凋亡及衰老等过程中发挥了重要的作用。鼠双微基因(murine double minute,MDM)2和MDMX(又称MDM4,murine double minute 4)是p53两个重要的调控因子。其中,MDMX能够通过与p53蛋白的相互作用以及转录后修饰来调节p53蛋白功能。虽然MDMX与MDM2蛋白结构同源,但是由于MDMX缺少E3连接酶,因此无法介导p53蛋白的降解。然而,MDMX本身能够通过分子内部结构的折叠与展开,与p53蛋白相互作用后调节其活性。在该过程中,MDMX的主要分子伴侣——CK1α(casein kinase 1 alpha)通过磷酸化MDMX并干扰其分子内部结合,从而协同调节p53蛋白。因而,MDMX及CK1α对p53蛋白的调节是一个多步骤、多因素参与的复杂过程。本文拟就MDMX以及CK1α对p53蛋白的具体调节机制进行综述。
As a tumor suppressor, p53 is activated by numerous cellular and environmental signals, and plays a criticalrole in the cell cycle regulation, cell apoptosis and senenscence. The murine double minute （MDM）2 and double minute mu？rine 4 （MDMX） are two important regulators. MDMX is a p53 binding protein with strong sequence homology to MDM2, but lacks ubiquitin ligase activity, and which is unable to target p53 for proteasomal degradation. MDMX regulates p53 activity through its binding with p53 and its postranscriptional modification. MDMX in the closed and open structure binds to p53 to regulate its activity. As the main partner of MDMX, casein kinase 1 alpha （CK1α） disrupts the intramolecular binding in MD？MX in the cooperation to regulate p53 activity. The process of MDMX and CK1αin the regulation of p53 is multi-step and complicated. In this paper the mechanism of MDMX and CK1αin the regulation of p53 protein was reviewed.
出处
《天津医药》
CAS
2015年第11期1338-1341,共4页
Tianjin Medical Journal
基金
国家自然科学基金青年项目(81401412)
