The specific role of PfArf1 in the transport of N-acylated PfAK2 to the PVM. Parasites expressing PfAK2-RFP and PfArf1-YFP-DD (A) or DD-YFP-PfRab1b

(C) were examined using the immunofluorescence assay. Fluorescence signals from RFP (red), YFP (green), and DAPI (blue) are shown. Wild-type PfArf1 or PfRab1b

(upper panels), the active mutant PfArf1Q71L or PfRab1bQ67L (middle panels), and the inactive mutant PfArf1T31N or PfRab1bS22N (lower panels) are shown. Representative images for PfAK2-RFP are shown and are divided into three patterns: peripheral PVM staining (PVM), faint signal (faint), and dot-like punctate signal within the parasites (punctate). The bars indicate 2 μm. The parasites that showed a signal for PfAK2-RFP were classified into three patterns based on the PfArf1-RFP expressing cells. the expression of active or inactive PfArf1 mutants inhibited PfAK2 transport to PVM (A), whereas the expression of active or inactive PfRab1b mutants had no effect (C). These results suggest that GTP hydrolysis by PfArf1 is required for proper PfAK2 recognition and further transport. The specific role of PfArf1 in the transport of PfAK2 was highlighted by the co-expression of PfRab1b mutants (C). In the co-expression with the wild-type DD-YFP-PfRab1b, active DDYFP-PfRab1bQ67L, or the inactive DD-YFP-PfRab1bS22N constructs, which corresponds human Rab1bQ67L and

Rab1bS22N, respectively, the transport of PfAK2-RFP was not inhibited and all parasites showed a peripheral pattern for their expression (PfRab1bWT: 99 ± 2%,

PfRab1bQ67L: 96 ± 4%, PfRab1bS22N: 94 ± 3%) (C).

Taku I, Hirai T, Makiuchi T, Shinzawa N, Iwanaga S, Annoura T, Nagamune K, Nozaki T, Saito-Nakano Y. Rab5b-Associated Arf1 GTPase Regulates Export of N-Myristoylated Adenylate Kinase 2 From the Endoplasmic Reticulum in Plasmodium falciparum. Front Cell Infect Microbiol. 2021 10:610200.