Inflammasome regulation by adaptor isoforms, ASC and ASCb, via differential self-assembly.
Inflammasome regulation by adaptor isoforms, ASC and ASCb, via differential self-assembly.
复制标题
DOI：
10.1016/j.jbc.2022.101566
复制
发表时间：
2022-03
期刊：
影响因子：
--
通讯作者：
de Alba E
中科院分区：
文献类型：
--
作者：
Diaz-Parga P;de Alba E
ASC是炎性小体的重要适配器，炎性小体是一种微米大小的多蛋白复合物，可处理促炎细胞因子。炎性小体的形成依赖于ASC通过其两个死亡结构域PYD和CARD的同型相互作用自缔合成大的组装体。ASCb是一种选择性剪接异构体，与ASC相比，其激活炎性小体的程度较低。因此，已经假设衔接子同种型差异调节炎性体功能。在氨基酸水平上，ASC和ASCb仅在连接两个死亡结构域的接头长度上不同。为了在分子水平上了解炎性小体调节，我们使用实时NMR、动态光散射（DLS）、尺寸排阻色谱和透射电子显微镜（TEM）研究了ASC和ASCb的自缔合特性。的NMR数据表明，ASC自缔合是快于ASCB的，这种低聚反应的动力学模型的结果在不同的值的反应级数和速率常数。此外，DLS分析表明，ASC自缔合成更紧凑的宏观结构相比，ASCb。最后，TEM数据显示，相对于ASC，ASCb形成致密细丝的倾向降低。总体而言，这些差异只能通过接头长度的影响来解释，因为NMR结果显示两种蛋白质中PYD和CARD的结构等效性。接头长度的影响通过与半胱氨酸天冬氨酸蛋白酶原-1 CARD结构域的分子对接得到证实。总之，我们的研究结果表明，ASC的更快和更少的多分散聚合是更有效的，合理地解释炎性小体激活差异的ASC亚型在分子水平上。
ASC is an essential adaptor of the inflammasome, a micrometer-size multiprotein complex that processes proinflammatory cytokines. Inflammasome formation depends on ASC self-association into large assemblies via homotypic interactions of its two death domains, PYD and CARD. ASCb, an alternative splicing isoform, activates the inflammasome to a lesser extent compared with ASC. Thus, it has been postulated that adaptor isoforms differentially regulate inflammasome function. At the amino acid level, ASC and ASCb differ only in the length of the linker connecting the two death domains. To understand inflammasome regulation at the molecular level, we investigated the self-association properties of ASC and ASCb using real-time NMR, dynamic light scattering (DLS), size-exclusion chromatography, and transmission electron microscopy (TEM). The NMR data indicate that ASC self-association is faster than that of ASCb; a kinetic model for this oligomerization results in differing values for both the reaction order and the rate constants. Furthermore, DLS analysis indicates that ASC self-associates into more compact macrostructures compared with ASCb. Finally, TEM data show that ASCb has a reduced tendency to form densely packed filaments relative to ASC. Overall, these differences can only be explained by an effect of the linker length, as the NMR results show structural equivalence of the PYD and CARD in both proteins. The effect of linker length was corroborated by molecular docking with the procaspase-1 CARD domain. Altogether, our results indicate that ASC’s faster and less polydisperse polymerization is more efficient, plausibly explaining inflammasome activation differences by ASC isoforms at the molecular level.
登录
查看更多内容
影响因子：
--
作者：
Diaz-Parga P;de Alba E
通讯作者：
de Alba E
影响因子：
8.7
作者：
Elliott EI;Sutterwala FS
通讯作者：
Sutterwala FS
影响因子：
8.8
作者：
Friker LL;Scheiblich H;Hochheiser IV;Brinkschulte R;Riedel D;Latz E;Geyer M;Heneka MT
通讯作者：
Heneka MT
DOI：
10.1073/pnas.71.12.4864
发表时间：
1974-01-01
影响因子：
11.1
作者：
HOFRICHTER, J;ROSS, PD;EATON, WA
通讯作者：
EATON, WA
影响因子：
8.7
作者：
Man SM;Kanneganti TD
通讯作者：
Kanneganti TD