Kumar M, Spandau D F
Department of Dermatology, Indiana University School of Medicine, Indianapolis 46202, USA.
Biochem Biophys Res Commun. 1995 Sep 14;214(2):744-53. doi: 10.1006/bbrc.1995.2348.
The detection of p53 in human keratinocytes is dependent on the specific anti-p53 monoclonal antibody that is used. Differences in antibody recognition are postulated to be due to the masking or exposure of particular epitopes in different conformations of p53. This study addresses the role of phosphorylation on p53-epitope accessibility in human keratinocytes. Keratinocytes were treated with the phosphatase inhibitor, okadaic acid, to determine the effect of inhibiting cellular phosphatases on p53 phosphorylation and epitope recognition. These studies suggest there is a correlation between the level of p53 phosphorylation and the antigenic reactivity of certain p53 epitopes in human keratinocytes. We also examined the ability of the catalytic subunits of protein phosphatase 1 and 2A to dephosphorylate p53 derived from human keratinocytes in vitro. These data suggest that PP2A may be the phosphatase that acts on p53 in cultured human keratinocytes.
在人角质形成细胞中p53的检测取决于所使用的特异性抗p53单克隆抗体。据推测，抗体识别的差异是由于p53不同构象中特定表位的掩盖或暴露所致。本研究探讨了磷酸化对人角质形成细胞中p53表位可及性的作用。用磷酸酶抑制剂冈田酸处理角质形成细胞，以确定抑制细胞磷酸酶对p53磷酸化和表位识别的影响。这些研究表明，人角质形成细胞中p53磷酸化水平与某些p53表位的抗原反应性之间存在相关性。我们还检测了蛋白磷酸酶1和2A的催化亚基在体外使源自人角质形成细胞的p53去磷酸化的能力。这些数据表明，PP2A可能是作用于培养的人角质形成细胞中p53的磷酸酶。
