Inhibition of protein N-myristoylation blocks < i > Plasmodium falciparum < /i > intraerythrocytic development, egress and invasion

by Anja C. Schlott, Ellen Knuepfer, Judith L. Green, Philip Hobson, Aaron J. Borg, Julia Morales-Sanfrutos, Abigail J. Perrin, Catherine Maclachlan, Lucy M. Collinson, Ambrosius P. Snijders, Edward W. Tate, Anthony A. Holder We have combined chemical biology and genetic modification approaches to investigate the importance of protein myristoylation in the human malaria parasite,Plasmodium falciparum. Parasite treatment during schizogony in the last 10 to 15 hours of the erythrocytic cycle with IMP-1002, an inhibitor ofN-myristoyl transferase (NMT), led to a significant blockade in parasite egress from the infected erythrocyte. Two rhoptry proteins were mislocalized in the cell, suggesting that rhoptry function is disrupted. We identified 16 NMT substrates for which myristoylation was significantly reduced by NMT inhibitor (NMTi) treatment, and, of these, 6 proteins were substantially reduced in abundance. In a viability screen, we showed that for 4 of these proteins replacement of the N-terminal glycine with alanine to prevent myristoylation had a substantial effect on parasite fitness. In detailed studies of one NMT substrate, glideosome-associated protein 45 (GAP45), loss of myristoylation had no impact on protein location or glideosome assembly, in contrast to the disruption caused by GAP45 gene deletion, but GAP45 myristoylation was essential for erythrocyte invasion. Therefore, there are at least 3 mechanisms by which inhibition of NMT can disrupt parasite development a...
Source: PLoS Biology: Archived Table of Contents - Category: Biology Authors: Source Type: research