Revisiting bacterial cytolethal distending toxin structure and function.
Revisiting bacterial cytolethal distending toxin structure and function.
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DOI：
10.3389/fcimb.2023.1289359
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发表时间：
2023
影响因子：
5.7
通讯作者：
中科院分区：
文献类型：
--
作者：
细胞致死性扩张毒素(CDTS)是一种细胞内作用的细菌基因毒素，由多种人类皮肤粘膜病原体产生。CDT必须成功地与宿主细胞的质膜结合，才能发挥其调节作用。最大的毒素活性需要所有三个毒素亚基CDtA、CDtB和CDtC，这些亚基主要基于高分辨率结构数据，被认为预先组装成毒素活性所必需的三方复合体。然而，生物活性毒素还没有被实验证明需要将这三个亚基组装成一个异三聚体。在这里，我们实验比较了空肠弯曲菌CDT(CJ-CDT)的浓度依赖的亚基相互作用和毒素细胞活性。免疫共沉淀和透析保留实验为异三聚体毒素复合体的存在提供了证据，但仅当CJ-CDtA、CJ-CDtB和CJ-CDtC的浓度比CJ-CDT介导的宿主细胞周期在G2/M界面停滞所需的浓度高几个对数时，这是由催化CJ-CDtB亚单位相关的内切酶活性触发的。微量热电泳法证实CJ-CDT亚基相互作用的亲和力较低。总之，我们的数据表明，在足以阻止细胞周期进展的最低浓度的毒素下，CJ-CDtA、CJ-CDtB和CJ-CDtC的混合物主要由非相互作用的亚单位单体组成。毒素三聚体结构和细胞活性之间缺乏一致性，这表明CDT主要毒化宿主细胞作为预组装的异源三聚体结构的广泛接受的模式应该被重新审视。
Cytolethal distending toxins (CDTs) are intracellular-acting bacterial genotoxins generated by a diverse group of mucocutaneous human pathogens. CDTs must successfully bind to the plasma membrane of host cells in order to exert their modulatory effects. Maximal toxin activity requires all three toxin subunits, CdtA, CdtB, and CdtC, which, based primarily on high-resolution structural data, are believed to preassemble into a tripartite complex necessary for toxin activity. However, biologically active toxin has not been experimentally demonstrated to require assembly of the three subunits into a heterotrimer. Here, we experimentally compared concentration-dependent subunit interactions and toxin cellular activity of the Campylobacter jejuni CDT (Cj-CDT). Co-immunoprecipitation and dialysis retention experiments provided evidence for the presence of heterotrimeric toxin complexes, but only at concentrations of Cj-CdtA, Cj-CdtB, and Cj-CdtC several logs higher than required for Cj-CDT-mediated arrest of the host cell cycle at the G2/M interface, which is triggered by the endonuclease activity associated with the catalytic Cj-CdtB subunit. Microscale thermophoresis confirmed that Cj-CDT subunit interactions occur with low affinity. Collectively, our data suggest that at the lowest concentrations of toxin sufficient for arrest of cell cycle progression, mixtures of Cj-CdtA, Cj-CdtB, and Cj-CdtC consist primarily of non-interacting, subunit monomers. The lack of congruence between toxin tripartite structure and cellular activity suggests that the widely accepted model that CDTs principally intoxicate host cells as preassembled heterotrimeric structures should be revisited.
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影响因子：
3.7
作者：
Dixon SD;Huynh MM;Tamilselvam B;Spiegelman LM;Son SB;Eshraghi A;Blanke SR;Bradley KA
通讯作者：
Bradley KA
影响因子：
6.7
作者：
Eshraghi A;Dixon SD;Tamilselvam B;Kim EJ;Gargi A;Kulik JC;Damoiseaux R;Blanke SR;Bradley KA
通讯作者：
Bradley KA
影响因子：
4.2
作者：
Burns DL
通讯作者：
Burns DL
影响因子：
3.4
作者：
Robb Huhn，G.;Torres-Mangual，Naly;Teter，Ken
通讯作者：
Teter，Ken
影响因子：
3.6
作者：
Cao, L;Volgina, A;DiRienzo, JM
通讯作者：
DiRienzo, JM