Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA.
Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA; Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA.
Biochim Biophys Acta Mol Cell Res. 2018 Nov;1865(11 Pt B):1846-1856. doi: 10.1016/j.bbamcr.2018.08.004. Epub 2018 Aug 10.
Toxoplasma gondii has a complex life cycle involving different hosts and is dependent on fast responses, as the parasite reacts to changing environmental conditions. T. gondii causes disease by lysing the host cells that it infects and it does this by reiterating its lytic cycle, which consists of host cell invasion, replication inside the host cell, and egress causing host cell lysis. Calcium ion (Ca) signaling triggers activation of molecules involved in the stimulation and enhancement of each step of the parasite lytic cycle. Ca signaling is essential for the cellular and developmental changes that support T. gondii parasitism. The characterization of the molecular players and pathways directly activated by Ca signaling in Toxoplasma is sketchy and incomplete. The evolutionary distance between Toxoplasma and other eukaryotic model systems makes the comparison sometimes not informative. The advent of new genomic information and new genetic tools applicable for studying Toxoplasma biology is rapidly changing this scenario. The Toxoplasma genome reveals the presence of many genes potentially involved in Ca signaling, even though the role of most of them is not known. The use of Genetically Encoded Calcium Indicators (GECIs) has allowed studies on the role of novel calcium-related proteins on egress, an essential step for the virulence and dissemination of Toxoplasma. In addition, the discovery of new Ca players is generating novel targets for drugs, vaccines, and diagnostic tools and a better understanding of the biology of these parasites.
刚地弓形虫具有复杂的生活史，涉及不同的宿主，并且依赖于快速的反应，因为寄生虫会对不断变化的环境条件做出反应。刚地弓形虫通过裂解它感染的宿主细胞来引起疾病，它通过重复其裂解周期来实现这一点，该周期包括宿主细胞入侵、在宿主细胞内复制和出芽导致宿主细胞裂解。钙离子（Ca）信号触发参与寄生虫裂解周期刺激和增强的分子的激活。Ca 信号对于支持刚地弓形虫寄生的细胞和发育变化是必不可少的。刚地弓形虫中 Ca 信号直接激活的分子参与者和途径的特征描述是粗略和不完整的。刚地弓形虫与其他真核模式生物系统之间的进化距离使得比较有时没有信息。适用于研究刚地弓形虫生物学的新基因组信息和新遗传工具的出现正在迅速改变这种情况。刚地弓形虫基因组揭示了许多可能涉及 Ca 信号的基因的存在，尽管它们中的大多数的作用尚不清楚。使用遗传编码钙指示剂（GECIs）已允许研究新型钙相关蛋白在出芽过程中的作用，出芽是刚地弓形虫毒力和传播的必要步骤。此外，新的 Ca 参与者的发现为药物、疫苗和诊断工具提供了新的靶标，并更好地理解了这些寄生虫的生物学。
