Mitochondrial behaviour throughout the lytic cycle of Toxoplasma gondii.
Mitochondrial behaviour throughout the lytic cycle of Toxoplasma gondii.
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DOI：
10.1038/srep42746
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发表时间：
2017-02-16
影响因子：
4.6
通讯作者：
Sheiner L
中科院分区：
文献类型：
--
作者：
Ovciarikova J;Lemgruber L;Stilger KL;Sullivan WJ;Sheiner L
线粒体在细胞中的分布控制着健康和疾病的细胞生理。在这里，我们描述了在真核单细胞寄生虫弓形虫裂解周期的不同阶段发现的线粒体形态和定位。由速殖子生命阶段驱动的溶解循环是急性弓形虫病的原因。众所周知，在宿主细胞内，速殖子在其外围维持其单个线粒体。我们发现，当寄生虫从宿主细胞过渡到细胞外基质时，线粒体形态发生了根本性的变化，导致外周接近性降低。这种变化在返回宿主后是可逆的，这表明在细胞内阶段发现了一种活跃的机制来维持外周定位。通过电子显微镜对这两种状态进行比较，发现了线粒体外膜和寄生虫膜之间的偶联区域，其特征表明存在膜接触位点，并且在细胞内和细胞外状态之间的过渡过程中其丰度发生了变化。这些新的观察结果为进一步研究弓形虫线粒体分布的分子机制以及这些线粒体变化对寄生虫生理的影响铺平了道路。
Mitochondria distribution in cells controls cellular physiology in health and disease. Here we describe the mitochondrial morphology and positioning found in the different stages of the lytic cycle of the eukaryotic single-cell parasite Toxoplasma gondii. The lytic cycle, driven by the tachyzoite life stage, is responsible for acute toxoplasmosis. It is known that whilst inside a host cell the tachyzoite maintains its single mitochondrion at its periphery. We found that upon parasite transition from the host cell to the extracellular matrix, mitochondrion morphology radically changes, resulting in a reduction in peripheral proximity. This change is reversible upon return to the host, indicating that an active mechanism maintains the peripheral positioning found in the intracellular stages. Comparison between the two states by electron microscopy identified regions of coupling between the mitochondrion outer membrane and the parasite pellicle, whose features suggest the presence of membrane contact sites, and whose abundance changes during the transition between intra- and extra-cellular states. These novel observations pave the way for future research to identify molecular mechanisms involved in mitochondrial distribution in Toxoplasma and the consequences of these mitochondrion changes on parasite physiology.