两个假定的Toxoplasma gondii形成孔的蛋白质,GRA47和GRA72,影响寄生虫的真空的小分子透性
Mebratu A Bitew1, Pablo S Gaete2, Christopher Swale3
1Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, USA.
mBio
|February 21, 2024
概括
毒菌使用GRA47和GRA72蛋白质在真空膜中形成通道,控制营养的流动. 破坏这些通道会损害寄生虫的生长和毒性,为毒素菌提供新的治疗点.
科学领域:
- 寄生虫学的寄生虫学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 淋巴状毒素是一种细胞内寄生虫,会引起严重的健康风险,特别是在免疫受损的个体中.
- 寄生虫在寄生虫真空体 (PVM) 中复制,通过其膜调节营养和废物交换.
- GRA 蛋白质对整个PVM的营养流量至关重要,GRA17 和 GRA23 之前被确定为孔形成蛋白质.
研究的目的:
- 为了研究GRA72的功能,一种在没有GRA17的情况下被认为是必不可少的蛋白质.
- 识别和描述参与PVM透性的GRA72的交互伙伴.
- 阐明GRA47和GRA72在营养物质运输和寄生虫毒性中的结构和功能作用.
主要方法:
- 免疫沉用于识别GRA72相互作用蛋白.
- 对GRA47和GRA72基因进行遗传删除 (Knockout).
- 淘汰寄生虫的表型分析,包括真空分子形态和小分子透性试验.
- 对GRA47和GRA72孔隙形成的计算结构预测.
- 保存的伊斯蒂丁残留物的位点定向突变发生.
- 电生理学证实毛孔功能和膜导电性变化.
- 在小鼠体内增殖测定和体内毒性研究.
主要成果:
- 鉴定出GRA47是一种GRA72.2的相互作用因子.
- 删除GRA47导致异常的"泡真空球"形态和减少小分子透性,类似于GRA17和GRA72淘汰赛.
- 结构预测表明,GRA47和GRA72分别形成了heptameric和hexameric孔隙,而关键的histidine残留物覆盖着孔隙.
- 突变分析和电生理学证实了这些histidines的孔隙形成能力和功能重要性.
- 在小鼠模型中,GRA47删除和histidine突变导致了体外寄生虫增殖的减少和毒性减弱.
结论:
- GRA47和GRA72是重要的毛孔形成蛋白质,它们调节了Toxoplasma gondii中的PVM透性.
- 这些蛋白质在营养物质运输,寄生虫生长和毒性方面发挥着关键作用.
- GRA47和GRA72代表了开发新抗毒素菌治疗方法的潜在治疗点.
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