Rab7 of Plasmodium falciparum is involved in its retromer complex assembly near the digestive vacuole

• Published in: Biochimica et biophysica acta. General subjects 2020-10, Vol.1864 (10), p.129656-129656, Article 129656
• Main Authors: Siddiqui, Asim Azhar, Saha, Debanjan, Iqbal, Mohd Shameel, Saha, Shubhra Jyoti, Sarkar, Souvik, Banerjee, Chinmoy, Nag, Shiladitya, Mazumder, Somnath, De, Rudranil, Pramanik, Saikat, Debsharma, Subhashis, Bandyopadhyay, Uday
• Format: Article
• Language: English
• Subjects: Antimalarials - pharmacology; Chloroquine - pharmacology; Digestive vacuole; GTPase; Humans; Magnesium - metabolism; Malaria, Falciparum - drug therapy; Malaria, Falciparum - metabolism; Malaria, Falciparum - parasitology; Models, Molecular; Plasmodium falciparum; Plasmodium falciparum - drug effects; Plasmodium falciparum - metabolism; Protein Interaction Maps - drug effects; rab GTP-Binding Proteins - metabolism; Rab7; Retromer complex; Vacuoles - drug effects; Vacuoles - metabolism
• ISSN: 0304-4165; 1872-8006
• DOI: 10.1016/j.bbagen.2020.129656

Background: Intracellular protein trafficking is crucial for survival of cell and proper functioning of the organelles; however, these pathways are not well studied in the malaria parasite. Its unique cellular architecture and organellar composition raise an interesting question to investigate. Methods: The interaction of Plasmodium falciparum Rab7 (PfRab7) with vacuolar protein sorting-associated protein 26 (PfVPS26) of retromer complex was shown by coimmunoprecipitation (co-IP). Confocal microscopy was used to show the localization of the complex in the parasite with respect to different organelles. Further chemical tools were employed to explore the role of digestive vacuole (DV) in retromer trafficking in parasite and GTPase activity of PfRab7 was examined. Results: PfRab7 was found to be interacting with retromer complex that assembled mostly near DV and the Golgi in trophozoites. Chemical disruption of DV by chloroquine (CQ) led to its disassembly that was further validated by using compound 5f, a heme polymerization inhibitor in the DV. PfRab7 exhibited Mg2+ dependent weak GTPase activity that was inhibited by a specific Rab7 GTPase inhibitor, CID 1067700, which prevented the assembly of retromer complex in P. falciparum and inhibited its growth suggesting the role of GTPase activity of PfRab7 in retromer assembly. Conclusion: Retromer complex was found to be interacting with PfRab7 and the functional integrity of the DV was found to be important for retromer assembly in P. falciparum. General significance: This study explores the retromer trafficking in P. falciparum and describes amechanism to validate DV targeting antiplasmodial molecules. •PfRab7 was shown to exhibit Mg2+ dependent intrinsic weak GTPase activity.•Rab7 GTPase inhibitor CID 1067700 suppressed the parasite growth.•Interaction of PfRab7 with retromer was shown by co-IP experiments.•PfRab7 and retromer were found to be closely associated with DV of the parasite.•Disruption of DV function by hemozoin inhibitors hampered the retromer assembly.