RAP1 contains a bipartite rhoptry signal. A RAP1-344 and RAP1-FL GFP fusions. Both constructs show a punctate fluorescence pattern characteristic of rhoptry localisation. For the RAP1-FL construct, GFP signal overlaps with RAMA. In contrast, the RAP1-344GFP chimera only partially overlaps with RAMA, suggesting rhoptry neck localisation. B. For the RAP1-344 construct, GFP co-localises with the rhoptry neck marker PfRON4. C. Immunoelectron microscopy demonstrates that truncated RAP1 (10 nm beads) in D10DRAP1 parasites is localised in the rhoptry neck, whereas full-length RAP1 in D10 (wild-type) parasites is localised in the rhoptry bulb. PfRON4 PF11_0168 (15 nm beads) is localised in the rhoptry neck in both parasite lines.

Richard D, Kats LM, Langer C, Black CG, Mitri K, Boddey JA, Cowman AF, Coppel RL. Identification of Rhoptry Trafficking Determinants and Evidence for a Novel Sorting Mechanism in the Malaria Parasite Plasmodium falciparum. PLoS Pathog. 2009 5(3):e1000328.