Molecular cloning and functional characterization of two forms of Pax8 in the rainbow trout, Oncorhynchus mykiss.
Molecular cloning and functional characterization of two forms of Pax8 in the rainbow trout, Oncorhynchus mykiss.
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DOI：
10.1016/j.ygcen.2013.12.009
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发表时间：
2014-03-01
影响因子：
2.7
通讯作者：
Suzuki, Masakazu
中科院分区：
文献类型：
--
作者：
Katagiri, Nobuto;Uemae, Youji;Sakamoto, Joe;Hidaka, Yoshie;Susa, Takao;Kato, Yukio;Kimura, Shioko;Suzuki, Masakazu
我们已经从虹鳟（Oncorhynchus mykiss）的甲状腺中鉴定出两种不同的Pax8 (a和b) mrna，它们似乎是由选择性剪接产生的。预计Pax8a和Pax8b蛋白都具有配对结构域、八肽和部分同源结构域，而Pax8b蛋白由于插入mRNA的编码区而缺乏羧基末端部分。RT-PCR分析显示，Pax8a和Pax8b mrna在甲状腺和肾脏中均大量表达。原位杂交组织化学进一步检测Pax8 mRNA在成年鳟鱼甲状腺滤泡上皮细胞和胚胎甲状腺原始细胞中的表达。双荧光素酶法研究Pax8a和Pax8b的功能特性。发现Pax8a增加了大鼠甲状腺过氧化物酶（TPO）启动子的转录调节，而Pax8b则没有。Pax8a进一步与大鼠Nkx2-1在人类TPO上游区域显示协同转录活性，包括增强子和启动子。另一方面，Pax8b降低了Pax8a与Nkx2-1的协同活性。电泳迁移率转移实验还表明，Pax8a和Pax8b都可以结合TPO启动子和增强子，这表明Pax8b的抑制作用可能是由于缺乏功能性羧基末端部分。综上所提，对于鳟鱼甲状腺，Pax8a可能与Nkx2-1合作直接增加TPO基因的表达，而Pax8b可能作为TPO转录的非激活竞争者。
We have identified two distinct Pax8 (a and b) mRNAs from the thyroid gland of the rainbow trout (Oncorhynchus mykiss), which seemed to be generated by alternative splicing. Both Pax8a and Pax8b proteins were predicted to possess the paired domain, octapeptide, and partial homeodomain, while Pax8b lacked the carboxy-terminal portion due to an insertion in the coding region of the mRNA. RT-PCR analysis showed each of Pax8a and Pax8b mRNAs to be abundantly expressed in the thyroid and kidney. In situ hybridization histochemistry further detected the expression of Pax8 mRNA in the epithelial cells of the thyroid follicles of the adult trout and in the thyroid primordial cells of the embryo. The functional properties of Pax8a and Pax8b were investigated by dual luciferase assay. The transcriptional regulation by the rat thyroid peroxidase (TPO) promoter was found to be increased by Pax8a, but not by Pax8b. Pax8a further showed synergistic transcriptional activity with rat Nkx2-1 for the human TPO upstream region including the enhancer and promoter. On the other hand, Pax8b decreased the synergistic activity of Pax8a and Nkx2-1. Electrophoretic mobility shift assay additionally indicated that not only Pax8a but also Pax8b can bind to the TPO promoter and enhancer, implying that the inhibitory effect of Pax8b might result from the lack of the functional carboxy-terminal portion. Collectively, the results suggest that for the trout thyroid gland, Pax8a may directly increase TPO gene expression in cooperation with Nkx2-1 while Pax8b may work as a non-activating competitor for the TPO transcription.
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影响因子：
5.3
作者：
MIZUNO, K;GONZALEZ, FJ;KIMURA, S
通讯作者：
KIMURA, S
影响因子：
2.7
作者：
Bjornsson, Bjorn Thrandur;Stefansson, Sigurd O.;McCormick, Stephen D.
通讯作者：
McCormick, Stephen D.
影响因子：
2.8
作者：
Lema, SC;Nevitt, GA
通讯作者：
Nevitt, GA
影响因子：
3.7
作者：
Di Palma T;Conti A;de Cristofaro T;Scala S;Nitsch L;Zannini M
通讯作者：
Zannini M
影响因子：
3.7
作者：
Di Palma, Tina;D'Andrea, Barbara;Zannini, Mariastella
通讯作者：
Zannini, Mariastella