State Key Laboratory of Genetic Engineering, School of Life Sciences, Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai 200438, China.
Key Laboratory of Marine Ecosystem and Biogeochemistry, Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China.
Proc Natl Acad Sci U S A. 2017 Oct 3;114(40):10642-10647. doi: 10.1073/pnas.1708194114. Epub 2017 Sep 19.
Recent findings have revealed that the protein gasdermin D (GSDMD) plays key roles in cell pyroptosis. GSDMD binds lipids and forms pore structures to induce pyroptosis upon microbial infection and associated danger signals. However, detailed structural information for GSDMD remains unknown. Here, we report the crystal structure of the C-terminal domain of human GSDMD (GSDMD-C) at 2.64-Å resolution. The first loop on GSDMD-C inserts into the N-terminal domain (GSDMD-N), which helps stabilize the conformation of the full-length GSDMD. Substitution of this region by a short linker sequence increased levels of cell death. Mutants F283A and F283R can increase protein heterogeneity in vitro and are capable of undergoing cell pyroptosis in 293T cells. The small-angle X-ray-scattering envelope of human GSDMD is consistent with the modeled GSDMD structure and mouse GSDMA3 structure, which suggests that GSDMD adopts an autoinhibited conformation in solution. The positive potential surface of GSDMD-N covered by GSDMD-C is exposed after being released from the autoinhibition state and can form high-order oligomers via a charge-charge interaction. Furthermore, by mapping different regions of GSDMD, we determined that one short segment is sufficient to kill bacteria in vitro and can efficiently inhibit cell growth in and These findings reveal that GSDMD-C acts as an auto-inhibition executor and GSDMD-N could form pore structures via a charge-charge interaction upon cleavage by caspases during cell pyroptosis.
最近的研究结果表明，蛋白gasdermin D（GSDMD）在细胞焦亡中发挥关键作用。GSDMD 与脂质结合并形成孔道结构，在微生物感染和相关危险信号的刺激下诱导细胞发生焦亡。然而，GSDMD 的详细结构信息仍不清楚。在这里，我们报道了人源 GSDMD（GSDMD-C）C 端结构域的晶体结构，分辨率为 2.64 Å。GSDMD-C 的第一个环插入到 N 端结构域（GSDMD-N）中，有助于稳定全长 GSDMD 的构象。用短连接序列取代该区域会增加细胞死亡水平。F283A 和 F283R 突变体在体外可以增加蛋白质异质性，并能够在 293T 细胞中发生细胞焦亡。人源 GSDMD 的小角 X 射线散射包络与模型化的 GSDMD 结构和鼠源 GSDMA3 结构一致，这表明 GSDMD 在溶液中采用自抑制构象。从自抑制状态释放后，GSDMD-N 上被 GSDMD-C 覆盖的正电势表面暴露出来，并可以通过电荷-电荷相互作用形成高级寡聚体。此外，通过对 GSDMD 的不同区域进行作图，我们确定一个短片段足以在体外杀死细菌，并能有效地抑制 和 中的细胞生长。这些发现表明，GSDMD-C 作为一个自抑制执行者，GSDMD-N 在细胞焦亡过程中被 caspase 切割后可以通过电荷-电荷相互作用形成孔道结构。
