Translational Inflammation Research, Medical Faculty, Center of Dynamic Systems, Otto von Guericke University, Magdeburg, Germany.
Integrated Biophysics and Structural Biology Lab, Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Mumbai, India.
Cell Chem Biol. 2024 Nov 21;31(11):1969-1985.e6. doi: 10.1016/j.chembiol.2024.06.014. Epub 2024 Jul 24.
Activation of procaspase-8 in the death effector domain (DED) filaments of the death-inducing signaling complex (DISC) is a key step in apoptosis. In this study, a rationally designed cell-penetrating peptide, DEDid, was engineered to mimic the h2b helical region of procaspase-8-DED2 containing a highly conservative FL motif. Furthermore, mutations were introduced into the DEDid binding site of the procaspase-8 type I interface. Additionally, our data suggest that DEDid targets other type I DED interactions such as those of FADD. Both approaches of blocking type I DED interactions inhibited CD95L-induced DISC assembly, caspase activation and apoptosis. We showed that inhibition of procaspase-8 type I interactions by mutations not only diminished procaspase-8 recruitment to the DISC but also destabilized the FADD core of DED filaments. Taken together, this study offers insights to develop strategies to target DED proteins, which may be considered in diseases associated with cell death and inflammation.
在诱导凋亡的信号复合物（DISC）的死亡效应结构域（DED）纤维中，procaspase-8 的激活是凋亡的关键步骤。在这项研究中，设计了一种合理的穿膜肽 DEDid，以模拟包含高度保守的 FL 基序的 procaspase-8-DED2 的 h2b 螺旋区。此外，在 procaspase-8 Ⅰ型界面的 DEDid 结合部位引入了突变。此外，我们的数据表明 DEDid 靶向其他Ⅰ型 DED 相互作用，如 FADD。阻断Ⅰ型 DED 相互作用的这两种方法均抑制了 CD95L 诱导的 DISC 组装、半胱天冬酶激活和细胞凋亡。我们表明，突变不仅减弱了 procaspase-8 募集到 DISC，而且还使 DED 纤维的 FADD 核心不稳定，从而抑制了 procaspase-8 Ⅰ型相互作用。总之，这项研究为开发针对 DED 蛋白的策略提供了思路，这些策略可能在与细胞死亡和炎症相关的疾病中得到考虑。
