Palmitoylation of Plasmodium alveolins promotes cytoskeletal function.

S-palmitoylation is a post-translational lipid modification that is widespread among Plasmodium proteins and essential for parasite development. Little is known about the contribution of palmitoylation to the function of individual parasite molecules and structures. Alveolins are major components of the subpellicular network (SPN), a cortical cytoskeleton primarily involved in providing mechanical strength to the cell. We show here that the alveolin IMC1c is palmitoylated on a conserved cysteine motif, and that non-palmitoylated IMC1c displays normal expression, stability and trafficking. However, mutant parasites exhibit reduced osmotic stress resistance and tensile strength. These findings support the hypothesis that alveolin palmitoylation enhances cytoskeletal function by strengthening the connection between the SPN and the adjoining inner membrane complex via lipid anchoring.