Thyroid hormone regulation of a transcriptional coactivator in Xenopus laevis:: Implication for a role in postembryonic tissue remodeling
Thyroid hormone regulation of a transcriptional coactivator in Xenopus laevis:: Implication for a role in postembryonic tissue remodeling
复制标题
DOI：
10.1002/dvdy.10075
复制
发表时间：
2002-04-01
影响因子：
2.5
通讯作者：
Shi, YB
中科院分区：
文献类型：
--
作者：
Amano, T;Leu, K;Shi, YB
甲状腺激素（TH）通过TH受体（TRs）调节基因转录而影响生物学过程。在TH的存在下，TR通过招募一个或多个属于不同组的转录共激活因子来激活靶基因转录。在这里，我们表明，在TH依赖的无尾两栖类变态，这样的共激活基因，非洲爪蟾同源的人Trip 7，TH上调。动力学研究表明，非洲爪蟾Trip 7是最有可能间接诱导TH的组织依赖性的方式。在肠道中，随着动物从草食性变为肉食性而经历广泛的重塑，Trip 7在变态期间但不是之前或之后以高水平表达。它也在其他生长或重塑组织中上调，如大脑和肢体，但不在退化的蝌蚪尾巴皮肤中。通过使用青蛙卵母细胞作为模型，我们表明，Trip 7影响基础转录的染色质结构依赖性的方式，但增强功能的配体TR的染色质结构的目标启动子无关。体外研究表明Trip 7直接与TR相互作用。这些结果表明，在非洲爪蟾变态，TH上调，虽然间接，Trip 7增强TR功能在幼虫到成人组织转化。发布2002 Wiley-Liss公司匕首
Thyroid hormone (TH) affects biological processes by regulating gene transcription through TH receptors (TRs). In the presence of TH, TR activates target gene transcription by recruiting one or more transcription coactivators belonging to diverse groups. Here, we demonstrate that during TH-dependent anuran metamorphosis, one such coactivator gene, the Xenopus laevis homolog of human Trip7, is up-regulated by TH. Kinetic studies suggest that Xenopus Trip7 is most likely induced indirectly by TH in a tissue-dependent manner. In the intestine, which undergoes extensive remodeling as the animal changes from being herbivorous to carnivorous, Trip7 is expressed at high levels during but not before or after metamorphosis. It is also up-regulated in other growing or remodeling tissues such as the brain and limb but not in degenerating tadpole tail skin. By using frog oocyte as a model, we show that Trip7 influences basal transcription in a chromatin structure-dependent manner but enhances the function of liganded TR regardless of the chromatin structure of the target promoter. In vitro studies indicate that Trip7 interacts directly with TR. These results suggest that during Xenopus metamorphosis, TH up-regulates, albeit indirectly, Trip7 to enhance TR function during larval-to-adult tissue transformation. Published 2002 Wiley-Liss, Inc.dagger