Random mutagenesis of PDZ(Omi) domain and selection of mutants that specifically bind the Myc proto-oncogene and induce apoptosis.
Random mutagenesis of PDZ(Omi) domain and selection of mutants that specifically bind the Myc proto-oncogene and induce apoptosis.
复制标题
PDZ(Omi)结构域的随机诱变以及特异性结合Myc原癌基因并诱导细胞凋亡的突变体的选择。
DOI：
10.1038/sj.onc.1206359
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发表时间：
2003
期刊：
影响因子：
8
通讯作者：
Zervos,AntonisS
中科院分区：
文献类型：
--
作者：
Junqueira,Daniela;Cilenti,Lucia;Musumeci,Lucia;Sedivy,JohnM;Zervos,AntonisS
Omi是一种哺乳动物丝氨酸蛋白酶，其定位于线粒体中并响应于凋亡刺激而释放至细胞质。Omi通过与X染色体连锁的凋亡抑制蛋白相互作用以半胱天冬酶依赖性方式诱导细胞死亡，以及以依赖于其蛋白水解活性的半胱天冬酶非依赖性方式诱导细胞死亡。Omi作为前体多肽合成，并加工成具有独特PDZ结构域的活性丝氨酸蛋白酶。PDZ结构域识别靶蛋白的末端羧基。据报道，能够折叠成β-指的内部肽也结合一些PDZ结构域。使用改良的酵母双杂交系统，PDZ Omi突变体通过其在酵母和哺乳动物细胞中结合人Myc癌蛋白的羧基末端的能力被分离。一个这样的PDZ m结构域（PDZ-M1），当转染到哺乳动物细胞，能够结合内源性Myc蛋白和诱导细胞死亡。PDZ-M1诱导的细胞凋亡完全依赖于Myc蛋白的存在，当使用c-myc空成纤维细胞时未观察到。我们的研究表明，Omi的PDZ结构域可以提供一个原型，可以很容易地利用它通过结合癌基因独特的羧基末端来特异性靶向并灭活癌基因。
Omi is a mammalian serine protease that is localized in the mitochondria and released to the cytoplasm in response to apoptotic stimuli. Omi induces cell death in a caspase-dependent manner by interacting with the X-chromosome linked inhibitor of apoptosis protein, as well as in a caspase-independent way that relies on its proteolytic activity. Omi is synthesized as a precursor polypeptide and is processed to an active serine protease with a unique PDZ domain. PDZ domains recognize the extreme carboxyl terminus of target proteins. Internal peptides that are able to fold into a β-finger are also reported to bind some PDZ domains. Using a modified yeast two-hybrid system, PDZ Omi mutants were isolated by their ability to bind the carboxyl terminus of human Myc oncoprotein in yeast as well as in mammalian cells. One such PDZ m domain (PDZ-M1), when transfected into mammalian cells, was able to bind to endogenous Myc protein and induce cell death. PDZ-M1-induced apoptosis was entirely dependent on the presence of Myc protein and was not observed when c-myc null fibroblasts were used. Our studies indicate that the PDZ domain of Omi can provide a prototype that could easily be exploited to target specifically and inactivate oncogenes by binding to their unique carboxyl terminus.