Identification and characterization of Bombyx mori homologs of Bonus, Mdm2, Rad6, Sce, and Synoviolin
Identification and characterization of Bombyx mori homologs of Bonus, Mdm2, Rad6, Sce, and Synoviolin
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DOI：
10.11416/jibs.90.2_021
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发表时间：
2021
影响因子：
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通讯作者：
J. B. H. Millado;Rina Hamajima;W. Sugiura;Shizuka Makino;Michihiro Kobayashi;M. Ikeda
中科院分区：
文献类型：
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作者：
J. B. H. Millado;Rina Hamajima;W. Sugiura;Shizuka Makino;Michihiro Kobayashi;M. Ikeda
肿瘤抑制蛋白p53作为细胞凋亡诱导的重要介质，通过翻译后修饰（包括泛素化）受到各种上游细胞因子的负调控。在这里，我们确定和特点的奖金，mdm 2，sce和滑膜蛋白与E3泛素连接酶活性，并与E2泛素结合酶活性，负调节p53水平，并有助于p53介导的细胞凋亡诱导果蝇和/或哺乳动物的rad 6家蚕同源物的编码区。在表征的B.家蚕同源物Bm-p53（B. p53的mori同源物）对单独的Bm-Mdm 2应答。RNAi介导的bm-mdm 2表达的敲低导致细胞Bm-p53水平增加，而Bm-Mdm 2的瞬时过表达导致细胞Bm-p53水平降低，表明Bm-Mdm 2在B中作为Bm-p53的负调节物起作用。森氏细胞尽管RNAi介导的bm-mdm 2表达敲低后Bm-p53水平显著增加，但在B中未检测到凋亡诱导或半胱天冬酶激活。在所用实验条件下，相反，Bm-p53和Bm-Mdm 2的瞬时共过表达减弱了Bm-p53诱导的细胞凋亡和效应物半胱天冬酶活性的B。mori细胞，而相应的转染质粒表达的Bm-p53水平没有明显降低。这些结果表明，Bm-Mdm 2是参与B细胞凋亡诱导的Bm-p53的主要负调控因子。森氏细胞
The tumor suppressor protein p53 serves as a crucial mediator of apoptosis induction and is negatively regulated by various upstream cellular factors through post-translational modifications, including ubiquitination. Here, we identified and characterized the coding region of Bombyx mori homologs of bonus, mdm2, sce, and synoviolin with E3 ubiquitin ligase activity, and rad6 with E2 ubiquitin conjugating enzyme activity, which negatively regulate p53 levels and contribute to p53-mediated apoptosis induction in Drosophila melanogaster and/or mammals. Among the characterized B. mori homologs, Bm-p53 (B. mori homolog of p53) responded to Bm-Mdm2 alone. RNAi-mediated knockdown of bm-mdm2 expression caused increased cellular Bm-p53 levels, whereas transient overexpression of Bm-Mdm2 resulted in reduced cellular Bm-p53 levels, indicating that Bm-Mdm2 functions as a negative regulator of Bm-p53 in B. mori cells. Despite considerable increase in Bm-p53 levels after RNAi-mediated knockdown of bm-mdm2 expression, apoptosis induction or caspase activation was undetectable in B. mori cells under the experimental conditions used. In contrast, transient co-overexpression of Bm-p53 and Bm-Mdm2 attenuated Bm-p53-induced apoptosis and effector caspase activity of B. mori cells without an appreciable reduction in Bm-p53 levels that are expressed by corresponding transfected plasmids. These results indicate that Bm-Mdm2 is the prime negative regulator for Bm-p53 involved in apoptosis induction of B. mori cells.