Plasmodium falciparum Rab5B is an N-terminally myristoylated Rab GTPase that is targeted to the parasite's plasma and food vacuole membranes.
Plasmodium falciparum (Pf) has a family of 11 Rab GTPases to regulate its vesicular transport. However, PfRab5B is unique in lacking a C-terminal geranyl-geranylation motif, while having N-terminal palmitoylation and myristoylation motifs. We show that the N-terminal glycine is required for PfRab5B myristoylation in vitro and when an N-terminal PfRab5B fragment possessing both acylation motifs is fused to GFP and expressed in transgenic P. falciparum parasites, the chimeric PfRab5B protein localizes to the plasma membrane. Upon substitution of the modified glycine by alanine the staining becomes diffuse and GFP is found in soluble subcellular fractions. Immuno-electron microscopy shows endogenous PfRab5B decorating the parasite's plasma and food vacuole membranes. Using reverse genetics rab5b couldn't be deleted from the haploid genome of asexual blood stage P. berghei parasites. The failure of PbRab5A or PbRab5C to complement for loss of PbRab5B function indicates non-overlapping roles for the three Plasmodium Rab5s, with PfRab5B involved in trafficking MSP1 to the food vacuole membrane and CK1 to the plasma membrane. We discuss similarities between Plasmodium Rab5B and Arabidopsis thaliana ARA6, a similarly unusual Rab5-like GTPase of plants.
Laboratoire de Biologie Cellulaire Comparative des Apicomplexes, Département d'Immunologie, Inflammation et Infection, Faculté de Médicine, Université Paris Descartes - Sorbonne Paris Cité, Paris, France ; Institut National de Recherche Médicale U1016, Centre National Recherche Scientifique UMR8104, Cochin Institute, Paris, France.
Carinne Ndjembo
CN
Ezougou
Laboratoire de Biologie Cellulaire Comparative des Apicomplexes, Département d'Immunologie, Inflammation et Infection, Faculté de Médicine, Université Paris Descartes - Sorbonne Paris Cité, Paris, France ; Institut National de Recherche Médicale U1016, Centre National Recherche Scientifique UMR8104, Cochin Institute, Paris, France.
Fathia
F
Ben-Rached
Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, United Kingdom.
David K
DK
Moss
Parasitology, Center of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands ; Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, United Kingdom.
Jing-Wen
JW
Lin
Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, United Kingdom.
Sally
S
Black
Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, United Kingdom.
Ellen
E
Knuepfer
Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, United Kingdom.
Judith L
JL
Green
Parasitology, Center of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.
Shahid M
SM
Khan
National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.
Amitabha
A
Mukhopadhyay
Parasitology, Center of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.
Chris J
CJ
Janse
Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States of America.
Isabelle
I
Coppens
Laboratoire de Biologie Cellulaire Comparative des Apicomplexes, Département d'Immunologie, Inflammation et Infection, Faculté de Médicine, Université Paris Descartes - Sorbonne Paris Cité, Paris, France ; Institut National de Recherche Médicale U1016, Centre National Recherche Scientifique UMR8104, Cochin Institute, Paris, France.
Hélène
H
Yera
Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, United Kingdom.
Anthony A
AA
Holder
Laboratoire de Biologie Cellulaire Comparative des Apicomplexes, Département d'Immunologie, Inflammation et Infection, Faculté de Médicine, Université Paris Descartes - Sorbonne Paris Cité, Paris, France ; Institut National de Recherche Médicale U1016, Centre National Recherche Scientifique UMR8104, Cochin Institute, Paris, France.
Gordon
G
Langsley
D000818:Animals; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism*; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D002479:Inclusion Bodies; D016778:Malaria, Falciparum / Q000378:metabolism* / Q000469:parasitology; D051379:Mice; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D019814:Myristic Acid / Q000737:chemistry* / Q000378:metabolism; D010588:Phagosomes; D010963:Plasmodium falciparum / Q000254:growth & development / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism*; D020696:rab5 GTP-Binding Proteins / Q000378:metabolism*
D011993:Recombinant Fusion Proteins; D019814:Myristic Acid; D049452:Green Fluorescent Proteins; D020696:rab5 GTP-Binding Proteins