Department of Biophysics, Kobe University Graduate School of Health Science, 7-10-2, Tomogaoka, Suma-ku, Kobe 654-0142, Japan.
Mol Cell Endocrinol. 2013 Aug 25;376(1-2):93-8. doi: 10.1016/j.mce.2013.05.022. Epub 2013 Jun 1.
PROP1 mutation causes combined pituitary hormone deficiency (CPHD). Several mutations are located in a transactivation domain (TAD) of Prop1, and the loss of TAD binding to cofactors is likely the cause of CPHD. PROP1 cofactors have not yet been identified. In the present study, we aimed to identify the PROP1-interacting proteins from the human brain cDNA library. Using a yeast two-hybrid assay, we cloned nine candidate proteins that may bind to PROP1. Of those nine candidates, amino-terminal enhancer of split (AES) was the most abundant, and we analyzed the AES function. AES dose-dependently decreased the PROP1-induced Pit-1 reporter gene expression. An immunoprecipitation assay revealed the relationship between AES and PROP1. In a mammalian two-hybrid assay, a leucine zipper-like motif of the AES Q domain was identified as a region that interacted with TAD. These results indicated that AES was a corepressor of PROP1.
PROP1 突变导致垂体激素缺乏症（CPHD）。几个突变位于 Prop1 的转录激活结构域（TAD）中，TAD 与辅助因子结合的丧失可能是 CPHD 的原因。PROP1 辅助因子尚未被鉴定。在本研究中，我们旨在从人脑 cDNA 文库中鉴定与 PROP1 相互作用的蛋白质。使用酵母双杂交测定，我们克隆了九个可能与 PROP1 结合的候选蛋白。在这九个候选蛋白中，氨基末端分裂增强子（AES）最为丰富，我们分析了 AES 的功能。AES 剂量依赖性地降低了 PROP1 诱导的 Pit-1 报告基因表达。免疫沉淀测定显示了 AES 和 PROP1 之间的关系。在哺乳动物双杂交测定中，鉴定出 AES Q 结构域的亮氨酸拉链样模体是与 TAD 相互作用的区域。这些结果表明 AES 是 PROP1 的核心抑制剂。
