Mapping C-terminal transactivation domains of the nuclear HER family receptor tyrosine kinase HER3.
Mapping C-terminal transactivation domains of the nuclear HER family receptor tyrosine kinase HER3.
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DOI：
10.1371/journal.pone.0071518
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Wheeler DL
中科院分区：
文献类型：
--
作者：
Brand TM;Iida M;Luthar N;Wleklinski MJ;Starr MM;Wheeler DL
近二十年来，人们在原发性肿瘤标本和癌细胞系中观察到核定位 HER 家族受体酪氨酸激酶 (RTK)。在细胞核内，HER 家族成员（EGFR、HER2 和 HER3）已被证明可作为各种促癌基因的共转录激活剂。然而，每个受体赋予转录潜力的区域仍然不明确。当前的研究旨在绘制 HER3 受体的推定反式激活域 (TAD) 图谱。为了实现这一目标，HER3 的各个细胞内区域与酵母转录因子 Gal4 (Gal4DBD) 的 DNA 结合域融合，并测试了它们反式激活 Gal4 UAS-荧光素酶的能力。这些分析结果表明，HER3 的 C 端结构域（CTD，酪氨酸激酶结构域远端的氨基酸）具有强大的反式激活潜力。接下来，构建了九个 HER3-CTD 截短突变体，以使用基于 Gal4 UAS-荧光素酶的系统绘制反式激活潜力的最小区域。这些分析确定了长度为 34 (B1) 和 27 (B2) 个氨基酸的二分区域，该区域赋予 HER3 的大部分反式激活潜力。接下来，我们确定了全长核 HER3 关联以及细胞周期蛋白 D1 启动子 122 bp 区域的调控。为了了解 B1 和 B2 区域如何影响核 HER3 的转录功能，我们进行了细胞周期蛋白 D1 启动子-荧光素酶测定，其中删除 B1 和 B2 区域的 HER3 对该启动子的调节受到严重阻碍。此外，HER3 的过表达增强了细胞周期蛋白 D1 mRNA 的表达，而 HER3 删除了其识别的 TAD 则阻碍了这种作用。因此，HER3 作为转录共激活因子的能力可能取决于特定的 C 端 TAD。
Nuclear localized HER family receptor tyrosine kinases (RTKs) have been observed in primary tumor specimens and cancer cell lines for nearly two decades. Inside the nucleus, HER family members (EGFR, HER2, and HER3) have been shown to function as co-transcriptional activators for various cancer-promoting genes. However, the regions of each receptor that confer transcriptional potential remain poorly defined. The current study aimed to map the putative transactivation domains (TADs) of the HER3 receptor. To accomplish this goal, various intracellular regions of HER3 were fused to the DNA binding domain of the yeast transcription factor Gal4 (Gal4DBD) and tested for their ability to transactivate Gal4 UAS-luciferase. Results from these analyses demonstrated that the C-terminal domain of HER3 (CTD, amino acids distal to the tyrosine kinase domain) contained potent transactivation potential. Next, nine HER3-CTD truncation mutants were constructed to map minimal regions of transactivation potential using the Gal4 UAS-luciferase based system. These analyses identified a bipartite region of 34 (B1) and 27 (B2) amino acids in length that conferred the majority of HER3’s transactivation potential. Next, we identified full-length nuclear HER3 association and regulation of a 122 bp region of the cyclin D1 promoter. To understand how the B1 and B2 regions influenced the transcriptional functions of nuclear HER3, we performed cyclin D1 promoter-luciferase assays in which HER3 deleted of the B1 and B2 regions was severely hindered in regulating this promoter. Further, the overexpression of HER3 enhanced cyclin D1 mRNA expression, while HER3 deleted of its identified TADs was hindered at doing so. Thus, the ability for HER3 to function as a transcriptional co-activator may be dependent on specific C-terminal TADs.
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影响因子：
21.3
作者：
Lin, SY;Makino, K;Hung, MC
通讯作者：
Hung, MC
影响因子：
9
作者：
Chiu, Connie G.;Masoudi, Hamid;Wiseman, Sam M.
通讯作者：
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影响因子：
5.7
作者：
Dittmann, Klaus;Mayer, Claus;Rodemann, H. Peter
通讯作者：
Rodemann, H. Peter
影响因子：
5.7
作者：
Dittmann, K;Mayer, C;Rodemann, HP
通讯作者：
Rodemann, HP
DOI：
10.1387/ijdb.103194hh
发表时间：
2010
期刊：
The International journal of developmental biology
影响因子：
--
作者：
Hirai H;Tani T;Kikyo N
通讯作者：
Kikyo N