Kojima T, Ikawa Y, Katoh I
Department of Retroviral Regulation, Medical Research Division, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
Biochem Biophys Res Commun. 2001 Mar;281(5):1170-5. doi: 10.1006/bbrc.2001.4486.
p51 in the p53 tumor suppressor family, also referred to as p63, encodes multiple isoforms including p51A (TAp63gamma) and p51B (TAp63alpha). The p53 protein forms a tetramer, and its stability and activity are regulated by molecular association with viral and cellular proteins and by biochemical modifications. Using a yeast two-hybrid system, the p51A and p51B isoforms were examined for homotypic and heterotypic interactions in the p53 family proteins and for their affinity to the p53-regulatory factors. Results indicate a homotypic interaction dependent on the presumed oligomerization domain of the p51 proteins. The possibility of a weak heterotypic interaction between p51 and p73 proteins was suggested, while association between p51 and p53 appeared improbable. Furthermore, unlike p53, the p51 proteins failed to display an affinity to SV40 large T antigen or MDM2-family proteins. Having several features in common with p53, the p51 proteins may function in biological processes apart from p53.
p53肿瘤抑制家族中的p51，也被称为p63，编码多种亚型，包括p51A（TAp63γ）和p51B（TAp63α）。p53蛋白形成四聚体，其稳定性和活性受与病毒及细胞蛋白的分子结合以及生化修饰的调节。利用酵母双杂交系统，研究了p51A和p51B亚型在p53家族蛋白中的同型和异型相互作用，以及它们与p53调节因子的亲和力。结果表明存在一种依赖于p51蛋白假定寡聚化结构域的同型相互作用。有人提出p51与p73蛋白之间可能存在弱异型相互作用，而p51与p53之间似乎不太可能发生结合。此外，与p53不同，p51蛋白对SV40大T抗原或MDM2家族蛋白没有亲和力。p51蛋白与p53有几个共同特征，可能在p53之外的生物过程中发挥作用。
