Toxoplasma gondii calcium-dependent protein kinase 3 (TgCDPK3)

Toxoplasma gondii calcium-dependent protein kinase 3 (TgCDPK3) is a plant-like serine/threonine kinase that serves as a critical signaling mediator in the life cycle of the protozoan parasite Toxoplasma gondii. It is primarily localized to the inner surface of the parasite's plasma membrane, where it regulates the rapid, calcium-dependent egress of tachyzoites from host cells. TgCDPK3 functions by phosphorylating key substrates, including the motor protein Myosin A, which activates gliding motility and triggers the secretion of microneme organelles necessary for exiting the host cell. Additionally, the kinase plays a role in the parasite's response to extracellular stress by acting as an elongation factor 2 (eEF2) kinase, thereby modulating protein synthesis. Because calcium-dependent protein kinases (CDPKs) are found in plants and apicomplexan parasites but are absent in mammals, TgCDPK3 is a highly attractive target for the development of selective anti-parasitic drugs. Small-molecule inhibitors, such as bumped kinase inhibitors (BKIs), have been shown to effectively block TgCDPK3 activity, leading to the arrest of the parasite's lytic cycle and providing a potential therapeutic strategy for treating toxoplasmosis.

Other names

TgCDPK3CDPK3Calcium-dependent protein kinase 3Toxoplasma gondii CDPK3

Inhibition of kinase activity to block calcium-dependent signaling pathways required for parasite egress and motility