RPEL proteins are the molecular targets for CCG-1423, an inhibitor of Rho signaling.
RPEL proteins are the molecular targets for CCG-1423, an inhibitor of Rho signaling.
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DOI：
10.1371/journal.pone.0089016
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Morita T
中科院分区：
文献类型：
--
作者：
Hayashi K;Watanabe B;Nakagawa Y;Minami S;Morita T
上皮间充质转化（EMT）与癌症和组织纤维化密切相关。心肌素相关转录因子A （MRTF-A/MAL/MKL1）的核积累在EMT中起着至关重要的作用。CCG-1423是一种新的Rho信号抑制剂，在CCG-1423处理的各种细胞中，MRTF-A的核积累被抑制。然而，这种抑制剂的分子靶点尚未确定。在本研究中，我们探讨了CCG-1423的作用机制。CCG-1423抑制MRTF-A与输入蛋白α/β1的相互作用，但不抑制单体G-actin与MRTF-A的结合。我们将Sepharose与CCG-1423 （CCG-1423 Sepharose）偶联来研究这一机制。使用CCG-1423 Sepharose的下拉实验显示CCG-1423与MRTF-A直接结合。此外，我们发现MRTF-A的n端基本结构域（NB）作为MRTF-A的功能性核定位信号（NLS），是CCG-1423的结合位点。G-actin不与CCG-1423 Sepharose结合，但在G-actin存在下，MRTF-A与CCG-1423 Sepharose的相互作用减弱。我们将这一结果归因于MRTF-A对G-actin的高结合亲和力以及NB靠近G-actin结合位点（RPEL基元）。因此，当MRTF-A与G-actin形成复合物时，CCG-1423与NB的结合有望被阻断。NF-E2相关因子2含有三种不同的富含碱性氨基酸的NLSs，不与CCG-1423 Sepharose结合，但其他含有rpel的蛋白如MRTF-B、心肌素和Phactr1与CCG-1423 Sepharose结合。这些结果表明，CCG-1423与含rpel蛋白的NLSs特异性结合。我们提出CCG-1423的抑制作用解释如下：当G-actin库耗尽时，CCG-1423特异性结合MRTF-A/B的NLS，阻止MRTF-A/B与输入蛋白α/β1的相互作用，从而抑制MRTF-A/B的核输入。
Epithelial–msenchymal transition (EMT) is closely associated with cancer and tissue fibrosis. The nuclear accumulation of myocardin-related transcription factor A (MRTF-A/MAL/MKL1) plays a vital role in EMT. In various cells treated with CCG-1423, a novel inhibitor of Rho signaling, the nuclear accumulation of MRTF-A is inhibited. However, the molecular target of this inhibitor has not yet been identified. In this study, we investigated the mechanism of this effect of CCG-1423. The interaction between MRTF-A and importin α/β1 was inhibited by CCG-1423, but monomeric G-actin binding to MRTF-A was not inhibited. We coupled Sepharose with CCG-1423 (CCG-1423 Sepharose) to investigate this mechanism. A pull-down assay using CCG-1423 Sepharose revealed the direct binding of CCG-1423 to MRTF-A. Furthermore, we found that the N-terminal basic domain (NB) of MRTF-A, which acts as a functional nuclear localization signal (NLS) of MRTF-A, was the binding site for CCG-1423. G-actin did not bind to CCG-1423 Sepharose, but the interaction between MRTF-A and CCG-1423 Sepharose was reduced in the presence of G-actin. We attribute this result to the high binding affinity of MRTF-A for G-actin and the proximity of NB to G-actin-binding sites (RPEL motifs). Therefore, when MRTF-A forms a complex with G-actin, the binding of CCG-1423 to NB is expected to be blocked. NF-E2 related factor 2, which contains three distinct basic amino acid-rich NLSs, did not bind to CCG-1423 Sepharose, but other RPEL-containing proteins such as MRTF-B, myocardin, and Phactr1 bound to CCG-1423 Sepharose. These results suggest that the specific binding of CCG-1423 to the NLSs of RPEL-containing proteins. Our proposal to explain the inhibitory action of CCG-1423 is as follows: When the G-actin pool is depleted, CCG-1423 binds specifically to the NLS of MRTF-A/B and prevents the interaction between MRTF-A/B and importin α/β1, resulting in inhibition of the nuclear import of MRTF-A/B.
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DOI：
10.1073/pnas.1233635100
发表时间：
2003-08-05
影响因子：
11.1
作者：
Li, SJ;Wang, DZ;Olson, EN
通讯作者：
Olson, EN
DOI：
10.1073/pnas.222561499
发表时间：
2002-11-12
影响因子：
11.1
作者：
Wang, DZ;Li, SJ;Olson, EN
通讯作者：
Olson, EN
DOI：
10.1152/ajprenal.00142.2007
发表时间：
2008-05-01
影响因子：
4.2
作者：
Elberg, Gerard;Chen, Lijuan;Turman, Martin A.
通讯作者：
Turman, Martin A.
影响因子：
16.6
作者：
Kanoh, N;Kumashiro, S;Osada, H
通讯作者：
Osada, H
DOI：
10.1073/pnas.0507346102
发表时间：
2005-10-18
影响因子：
11.1
作者：
Oh, JY;Richardson, JA;Olson, EN
通讯作者：
Olson, EN