Sinenko Sergey A
Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
Institute of Cytology, Russian Academy of Sciences, Saint Petersburg 194064, Russia.
Oncotarget. 2017 Jul 31;8(41):70452-70462. doi: 10.18632/oncotarget.19715. eCollection 2017 Sep 19.
have been used to identify new components in apoptosis regulation. The protein Dark forms an octameric apoptosome complex that induces the initiator caspase Dronc to trigger the caspase cell death pathway and, therefore, plays an important role in controlling apoptosis. Caspases and Dark are constantly expressed in cells, but their activity is blocked by DIAP1 E3 ligase-mediated ubiquitination and subsequent inactivation or proteasomal degradation. One of the regulatory mechanisms that stabilize proapoptotic factors is the removal of ubiquitin chains by deubiquitinases. In this study performed a modified genetic screen for deubiquitinases (dsRNA lines) to identify those involved in stabilizing proapoptotic components. Loss-of-function alleles of deubiquitinase were identified as suppressors of the Dronc overexpression phenotype. deficiency also suppresses apoptosis induced by the RHG protein, Grim. Genetic analysis revealed for the first time that deficiency sufficiently suppresses the Dark phenotype, indicating its involvement in the control of Dark/Dronc apoptosome function in invertebrate apoptosis.
已被用于识别细胞凋亡调控中的新成分。Dark蛋白形成一种八聚体凋亡小体复合物，该复合物诱导起始半胱天冬酶Dronc触发半胱天冬酶细胞死亡途径，因此在控制细胞凋亡中起重要作用。半胱天冬酶和Dark在细胞中持续表达，但其活性被DIAP1 E3连接酶介导的泛素化以及随后的失活或蛋白酶体降解所阻断。稳定促凋亡因子的调控机制之一是通过去泛素酶去除泛素链。在本研究中，对去泛素酶（dsRNA品系）进行了改良的遗传筛选，以鉴定那些参与稳定促凋亡成分的去泛素酶。去泛素酶的功能缺失等位基因被鉴定为Dronc过表达表型的抑制因子。其缺陷也抑制了由RHG蛋白Grim诱导的细胞凋亡。遗传分析首次揭示其缺陷足以抑制Dark表型，表明其参与无脊椎动物细胞凋亡中Dark/Dronc凋亡小体功能的控制。
