Ma Xi, Zhao Hongshan, Shan Jingxuan, Long Feng, Chen Yaoyao, Chen Yingyu, Zhang Yingmei, Han Xiao, Ma Dalong
Department of Immunology, School of Basic Medicine, and Human Disease Genomics Center, Peking University, Beijing 100083, China.
Mol Biol Cell. 2007 Jun;18(6):1965-78. doi: 10.1091/mbc.e06-07-0608. Epub 2007 Mar 14.
PDCD10 (programmed cell death 10, TFAR15), a novel protein associated with cell apoptosis has been recently implicated in mutations associated with Cerebral Cavernous Malformations (CCM). Yeast two-hybrid screening revealed that PDCD10 interacts with MST4, a member of Ste20-related kinases. This interaction was confirmed by coimmunoprecipitation and colocalization assays in mammalian cells. Furthermore, the co-overexpression of PDCD10 and MST4 promoted cell proliferation and transformation via modulation of the extracellular signal-regulated kinase (ERK) pathway. Potent short interfering RNAs (siRNAs) against PDCD10 (siPDCD10) and MST4 (siMST4) were designed to specifically inhibit the expression of PDCD10 and MST4 mRNA, respectively. The induction of siPDCD10 or siMST4 resulted in decreased expression of endogenous PDCD10 or MST4, which was accompanied by reduced ERK activity and attenuated cell growth and anchorage-independent growth. On the other hand, siMST4 had similar effects in PDCD10-overexpressed cells. And more importantly, we confirmed that either overexpressing or endogenous PDCD10 can increase the MST4 kinase activity in vitro. Our results demonstrated that PDCD10 modulation of ERK signaling was mediated by MST4, and PDCD10 could be a regulatory adaptor necessary for MST4 function, suggesting a link between cerebral cavernous malformation pathogenesis and the ERK-MAPK cascade via PDCD10/MST4.
PDCD10（程序性细胞死亡10，TFAR15）是一种与细胞凋亡相关的新型蛋白质，最近被发现与脑海绵状血管畸形（CCM）相关的突变有关。酵母双杂交筛选显示，PDCD10与Ste20相关激酶家族成员MST4相互作用。这种相互作用在哺乳动物细胞中通过免疫共沉淀和共定位分析得到证实。此外，PDCD10和MST4的共过表达通过调节细胞外信号调节激酶（ERK）途径促进细胞增殖和转化。针对PDCD10（siPDCD10）和MST4（siMST4）设计了有效的短发夹RNA（shRNA），分别特异性抑制PDCD10和MST4 mRNA的表达。siPDCD10或siMST4的导入导致内源性PDCD10或MST4表达降低，同时伴随着ERK活性降低以及细胞生长和非锚定依赖性生长减弱。另一方面，siMST4在PDCD10过表达的细胞中具有类似的作用。更重要的是，我们证实在体外过表达或内源性PDCD10均可增加MST4激酶活性。我们的结果表明，PDCD10对ERK信号的调节是由MST4介导的，并且PDCD10可能是MST4功能所必需的调节衔接蛋白，提示通过PDCD10/MST4在脑海绵状血管畸形发病机制与ERK-MAPK级联反应之间存在联系。
