Toxoplasma ISP4 is a central IMC Sub-compartment Protein whose localization depends on palmitoylation but not myristoylation

► ISP4 is a fourth member of the ISP family of Toxoplasma IMC proteins. ► ISP4 localizes to the central IMC sub-compartment. ► ISP4 is subject to ISP1-dependent apical cap exclusion, similar to ISP2/3. ► In contrast to other ISPs, myristoylation does not play a role in ISP4 targeting. ► ISP4 targeting is dependent upon cysteine residues predicted for palmitoylation.