FIGURE 9.
Mutational analysis of the minimal sequence requirements for IMC association of PfISP1. A and B, expressions of the first 11 (11PfSP1-GFP, A) or 10 (10PfISP1-GFP, B) amino acids are sufficient to direct GFP to the IMC (panels A1–B1). C, substitution of D11 with lysine (11PfISP1D11K-GFP, C) abolishes IMC targeting (panel C1) and leads to peripheral localization. The zoom highlights its additional association with the food vacuole membrane consistent with plasma membrane association. Panel C2, co-localization with the IMC marker GAPM2. Nascent IMC (anti-GAPM2, red) is clearly distinguishable from the peripherally associated 11PfISP1D11K-GFP in early stages (T1) and congruent in late stages (T3). Panel C3, Western blot analysis using anti-GFP antibodies. DIC, differential interference contrast.