The Organization and Function of the Toxoplasma Daughter Cell Scaffold

Uncontrolled Toxoplasma growth is the primary mechanism by which the parasite causes
severe and life-threatening disease. The parasite replicates by a process termed endodyogeny,
where two daughter parasites form within a single mother. A key step in endodyogeny is formation
of the daughter cell inner membrane complex, which is an unique organelle that lies directly
underneath the plasma membrane and is required for parasite motility and replication. During
daughter cell development, the nascent IMC emerges from a complex named the daughter cell
scaffold (DCS). Despite its importance, the DCS is poorly characterized and few of its constituent
proteins are known. Here, we hypothesize that the Toxoplasma F-box protein, TgFBXO1, is a
critical component of the DCS. To test our hypothesis, we will determine: i) how TgFBXO1 is
targeted to the DCS, ii) how TgFBXO1 regulates inner membrane complex development and
organization, and iii) which TgFBXO1-interacting proteins are important for inner membrane
complex development. Together, these studies will provide in depth mechanistic detail for a
protein complex that is critical for growth of an important protozoan pathogen. Furthermore, they
were serve as a springboard for future studies aimed at developing novel anti-parasitic drugs that
function by targeting this complex.

Grant Number: 7R01AI150240-06
NIH Institute/Center: NIH
Principal Investigator: Ira Blader