Global analysis of palmitoylated proteins in Toxoplasma gondii

Summary

Post-translational modifications (PTMs) such as palmitoylation are critical for the lytic cycle of the protozoan parasite Toxoplasma gondii. While palmitoylation is involved in invasion, motility, and cell morphology, the proteins that utilize this PTM remain largely unknown. Using a chemical proteomic approach, we report a comprehensive analysis of palmitoylated proteins in T. gondii, identifying a total of 282 proteins, including cytosolic, membrane-associated and transmembrane proteins. From this large set of palmitoylated targets, we validate palmitoylation of proteins involved in motility (myosin light chain 1, myosin A), cell morphology (PhIL1), and host-cell invasion (apical membrane antigen 1, AMA1). Further studies reveal that blocking palmitoylation enhances the release of AMA1 and other invasion-related proteins from apical secretory organelles, suggesting that AMA1 controls this secretion process. These findings suggest that palmitoylation is ubiquitous throughout the T. gondii proteome and reveal insights into the biology of this important human pathogen.

Graphical abstract