Choi, Charles P. (2015 - 2016)

Charles is in the Immunity, Microbes & Molecular Pathogenesis home area of the MBIDP.  He joined the CMB training program in 2015.  His research mentor is Dr. Peter Bradley.  He received a B.S. degree in 2013 from UCLA.

Mentor: Dr. Peter Bradley

Research project:

Functional Analysis of a Rhoptry Protein Complex Critical for Invasion by Toxoplasma gondii

Toxoplasma gondii is estimated to have infected one third of the world’s population. While life-long infection is typically asymptomatic, immunocompromised individuals and fetuses risk developing fatal symptoms of toxoplasmosis, such as encephalitis and brain lesions. Due to its relative ease of culturing in the laboratory and a well-established set of tools for genetic manipulation, T. gondii also serves as a model organism for the study of related pathogens belonging to the phylum Apicomplexa, such as the malaria-causing Plasmodium spp., which claims around 600,000 lives per year.

T. gondii is an obligate intracellular parasite that has specialized organelles that enable it to invade its host cell and form a replication-permissive niche. One of these, the rhoptry, is a secretory organelle at the apical end of the parasite that releases proteins responsible for active penetration of the host cell. Our lab has shown that proper apical rhoptry positioning is mediated by a palmitoylated armadillo-repeat protein TgARO that localizes to the cytoplasmic face of the organelle. Conditional knockdown of TgARO disrupts apical tethering and completely abrogates invasion. I am exploring the application of various biochemical techniques such as chemical crosslinking of the TgARO complex as a means to study the precise mechanism by which this essential protein enables pathogenicity of this parasite.