Characterization of Toxoplasma gondii Calcium regulator proteins TGGT1_253640 and TGGT1_222060 for Toxoplasma gondii growth and invasion

Toxoplasma gondii is an opportunistic apicomplexan parasite infecting humans and livestock. Infection in immunocompromised individuals can cause neurological damage and infection during pregnancy can lead to fetal death. These parasites engage in a complex life cycle, involving repeated invasion of the host cell and egress from the host cell. Calcium signaling is an important regulatory mechanism for many essential processes in the parasite, including gliding motility (actomyosin-dependent mode of motion), invasion, and egress. Our work here focuses on two previously uncharacterized calcium regulator proteins (TGGT1_253640 and TGGT1_222060). To characterize the role of these proteins in parasite viability and calcium regulation, we fused an auxin degron system using CRISPR-cas9 gene modification technique. We have localized the TGGT1_253640 to endoplasmic reticulum of the parasite. The protein is downregulated upon the addition of auxin as early as four hours thus providing a tool to study the function of the protein. Future work aims to determine the role of these proteins in parasite growth and fitness using growth and replication assays