The suppressor of metastasis Nm23-H1 interacts with the Cdc42 Rho family member and the pleckstrin homology domain of oncoprotein Dbl-1 to suppress cell migration
The suppressor of metastasis Nm23-H1 interacts with the Cdc42 Rho family member and the pleckstrin homology domain of oncoprotein Dbl-1 to suppress cell migration
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DOI：
10.4161/cbt.7.5.5665
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发表时间：
2008-05-01
影响因子：
3.6
通讯作者：
Robertson, Erle S.
中科院分区：
文献类型：
--
作者：
Murakami, Masanao;Meneses, Patricio I.;Robertson, Erle S.
肿瘤的侵袭和转移是由许多已知参与信号传导和细胞骨架重排的细胞分子调节的。肿瘤转移抑制因子Nm 23-H1是其中之一，它与人类肿瘤的侵袭性和转移潜能有关。nm 23-H1在人黑色素瘤和浸润性乳腺癌中表达下调最近的研究表明，Nm 23-H1和癌蛋白Dbl-1之间的关联，Dbl-1与鸟嘌呤交换有关，属于鸟嘌呤交换因子（GEF）家族。在本报告中，我们显示了在体外和在人B细胞中的直接相互作用，并特别鉴定了Dbl-1的普列克底物蛋白同源结构域作为与Nm 23-H1结合的结构域。此外，Nm 23-H1和Dbl-1共定位于CCS-7细胞的细胞质中，当外源表达时，在细胞的周边，特别是在质膜上显示出主要的信号。有趣的是，Dbl-1和Cdc 42表达在细胞迁移测定中拯救了Nm 23-H1的抑制活性。我们发现Cdc 42是一种参与细胞骨架重组、细胞生长和发育的调节蛋白，可以与Nm 23-H1和激酶缺陷突变体H118 F结合，但与缺乏抑制细胞迁移和转移能力的突变体P96 S结合很弱。Cdc 42还与Nm 23-H1和Dbl-1蛋白共定位，作为细胞质和细胞膜上的特异性点状信号。当用Dbl-1和Cdc 42表达时，Nm 23-H1也导致膜皱褶和突起的减少。令人惊讶的是，Nm 23-H1与Cdc 42以及Rac 1相互作用，但与RhoA的相互作用稍弱。这些研究表明，Nm 23-H1可以通过与Dbl-1相互作用调节Cdc 42和可能的其他Rho家族成员的活性来负调节细胞迁移和肿瘤转移。
Tumor invasion and metastasis is regulated by a number of cellular molecules known to be involved in signaling and cytoskeletal rearrangement. One of these molecules is the suppressor of tumor metastasis Nm23-H1 which linked to invasiveness and metastatic potential of human cancers. Nm23-H1 expression is downregulated in human melanoma and invasive breast carcinoma. Recent studies have shown an association between the Nm23-H1 and oncoprotein Dbl-1 which is associated with guanine exchange and belongs to a family of Guanine Exchange Factors (GEF). In this report we show a direct interaction in vitro and in human B cells and specifically identified the pleckstrin homology domain of Dbl-1 as the domain which binds to Nm23-H1. Furthermore, Nm23-H1 and Dbl-1 colocalized in the cytoplasm of CCS-7 cells when expressed exogenously and showed predominant signals at the periphery of the cells particularly at the plasma membrane. Interestingly, Dbl-1 and Cdc42 expression rescued the suppressive activities of Nm23-H1 in cell migration assays. We show that Cdc42 a regulatory protein involved in cytoskeletal reorganization, cell growth and development can bind to Nm23-H1 and the kinase deficient mutant H118F but only weakly to the mutant P96S which lacks the ability to suppress cell migration and metastasis. Cdc42 also colocalized with Nm23-H1 and the Dbl-1 proteins as specific punctate signals in the cytoplasm and at the cell membrane. Nm23-H1 also lead to the reduction in membrane ruffles and protuberances when expressed with Dbl-1 and Cdc42. Suprisingly, Nm23-H1 interacted with Cdc42 as well as Rac1 but somewhat weaker with RhoA. These studies suggests that Nm23-H1 can negatively regulate cell migration and tumor metastasis by modulating the activity of Cdc42 and possibly other Rho family members through interaction with Dbl-1.