一种控制细胞循环进展的细菌毒素,作为脱氧核糖酶I类蛋白质控制细胞循环进展
1Section of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale School of Medicine, New Haven, CT 06536, USA.
概括
细菌细胞杀伤性扩张毒素 (CDT) 子单元CdtB,一种脱氧核糖酶,导致细胞循环停止和死亡. 缺乏脱氧核糖核酶活性的突变体不会诱导这些毒性作用.
科学领域:
- 微生物学 微生物学
- 细胞生物学 细胞生物学
- 毒理学 毒理学 毒理学
背景情况:
- 细菌病原体利用诸如细胞杀伤性扩张毒素 (CDT) 等毒素诱导宿主细胞死亡.
- CDT导致细胞循环停止,细胞质膨胀,染色质碎片化和细胞死亡.
- 坎皮洛巴克特 (Campylobacter jejuni) 的CDT毒素子单元CdtB具有I型脱氧核糖核酶活性.
研究的目的:
- 研究CdtB的脱氧核糖核酶活性在CDT诱导的细胞毒性中的作用.
- 要确定CdtB的酶功能是否对毒素对宿主细胞的影响至关重要.
主要方法:
- 在培养细胞中CdtB的短暂表达.
- 微注射纯化的CdtB及其突变体.
- 对细胞形态,细胞循环进展和色素完整性的分析.
- CdtB的位点定向突变发生,以破坏催化或结合残留物.
主要成果:
- 暂时的CdtB表达导致培养细胞中显著的染色质破坏.
- 微注射CdtB诱导了细胞质膨胀和细胞循环停止.
- 缺陷脱氧核糖酶活性的CdtB突变未能破坏染色质或阻止细胞循环.
- 含有突变CdtB的全毒素没有诱导细胞循环停止或形态变化.
结论:
- CdtB的脱氧核糖酶活性对于其在细胞缩毒素中介细胞循环停止和死亡中的作用至关重要.
- 对于观察到的CDT的细胞毒性作用,CdtB的酶功能是必要的.
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