弓形虫SNARE蛋白在分泌性细胞器生物发生过程中的作用机制研究

Toxoplasma gondii is an obligate intracellular parasite of Apicomplexa. This parasite could cause infection in many animals and human being and lead to important zoonotic diseases. T. gondii possesses a highly polarized secretory system, and through which, parasites secret large amount of proteins outside of parasites and into host cells. These secretory proteins are critical for invasion and survival of parasites. Therefore, it is important to understand how this parasite regulate transportation of secretory proteins, biogenesis of secretory organells and protein secretion for development of therapeutic tools against toxoplasmosis. The recent findings suggest that T. gondii has functionally repurposed evolutionarily conserved regulators of the endosomal system to the secretory pathway to transport secretory proteins and form secretory organelles. However, it is still not clear how the biogenesis of secretory organells is regulated in T. gondii. SNARE family proteins are major mediators of vehicle fusion in eukaryotic cells. In this study, the function of SNARE proteins on the biogenesis of secretory organells will be investigated through conditional knockout methods. The components of related SNARE complex will be identified through immnoprecipitation assay. Furthermore, the subcellular localization of the SNAREs and their interactions will be studied to elucidate the molecular mechanism involved in the biogenesis of secretory organells. The findings of this study will provide a theoretical basis for the development of therapeutic measurements against T. gondii.

弓形虫是一种专性细胞内寄生的原虫，能够广泛感染人和恒温动物有核细胞，引起重要的人兽共患寄生虫病。弓形虫需要通过高度极化的分泌性细胞器分泌大量感染相关蛋白，从而入侵宿主细胞和建立感染。因此，了解弓形虫分泌蛋白转运的分子机制对弓形虫病防控具有重要的意义。但是目前弓形虫分泌性细胞器生物发生的分子机制尚不清楚。本项目拟筛选相关SNARE蛋白，采用条件性敲除等方法研究弓形虫SNARE蛋白在分泌性细胞器生物发生过程中的作用；利用免疫共沉淀等方法鉴定相应SNARE复合物；通过免疫荧光实验等方法分析相应SNARE复合物蛋白在细胞内的定位和复合物分子间的相互作用，进而阐明SNARE蛋白及相关复合物在弓形虫分泌性细胞器生物发生过程中发挥功能的分子机制。本项目的研究成果将为开发弓形虫病治疗手段提供理论依据。