Conditional Protein Degradation Tool for Cryptosporidium

Sumiti Vinayak of the University of Georgia in the U.S. will develop a genetic tool to rapidly turn genes off using light in order to study the function of essential genes in the intestinal parasite Cryptosporidium and accelerate drug discovery. Cryptosporidium causes chronic diarrhea and can lead to death in young children. There is currently only one drug available and it is not effective in many patients. New drugs can be developed based on a detailed understanding of the function of essential proteins, however this has been challenging in Cryptosporidium because it is not possible to control when a protein is degraded. They will develop a construct that fuses a protein of interest to a light-inducible domain carrying a hidden degradation signal. When exposed to blue light, this signal is activated, leading to protein degradation at a selected time. They will first optimize their system in vitro using the nanoluciferase gene and C. parvum sporozoites. They will then test it on a candidate essential protein by establishing a stable transgenic parasite cell line to infect mice. Oocysts containing the recombined constructs will then be isolated from the mice and used to infect a human intestinal cell line. After exposing these cells to blue light, they will use microscopy to analyze the effect of degrading the essential protein on the parasite's life cycle.