title: Identification of a new developmentally regulated Leishmania major large RAB GTPase.
abstract: Here, we describe for the first time a Leishmania specific gene encoding a large 610 amino-acid RAB GTPase (LmLRAB). LmLRAB displays high homologies with the RAB GTPase protein family between amino acids 34 and 284. It contains characteristic signatures of RAB proteins: 4 GTP binding domains, 5 RAB specific domains, 3 RAB subfamily-specific domains, and a prenylation site. lmlrab is a single copy gene, transcribed as a 3.5 kb mRNA, highly conserved in Leishmania species, and encodes a protein doublet of approximately 75 kDa. Immunofluorescence microscopy using LmLRAB-specific antibodies demonstrated that LmLRAB is confined in a structure adjacent to the kinetoplast probably corresponding to an early endosomal/golgi apparatus localization. Interestingly, using quantitative real-time RT-PCR, we showed that the lmlrab gene is up-regulated twice in amastigotes relative to promastigotes. These findings suggest that LmLRAB may play a potential role in Leishmania pathogenicity.
authors.affiliation: Laboratoire d'Immunopathologie, Vaccinologie et Génétique Moléculaire, Institut Pasteur de Tunis, 13, Place Pasteur 1002 Tunis-Belvédère, Tunisia. mehdi.chenik@pasteur.rns.tn
authors.forename: Mehdi
authors.initials: M
authors.lastname: Chenik
authors.forename: Noura
authors.initials: N
authors.lastname: Chaabouni
authors.forename: Yosser
authors.initials: Y
authors.lastname: Ben Achour-Chenik
authors.forename: Meriem
authors.initials: M
authors.lastname: Ouakad
authors.forename: Inès
authors.initials: I
authors.lastname: Lakhal-Naouar
authors.forename: Hechmi
authors.initials: H
authors.lastname: Louzir
authors.forename: Koussay
authors.initials: K
authors.lastname: Dellagi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D015153:Blotting, Western; D002454:Cell Differentiation; D003001:Cloning, Molecular; D019295:Computational Biology; D018076:DNA, Complementary / Q000378:metabolism; D004705:Endocytosis; D005089:Exocytosis; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D018320:Leishmania major / Q000201:enzymology* / Q000472:pathogenicity; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D016366:Open Reading Frames; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D020691:rab GTP-Binding Proteins / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D011994:Recombinant Proteins; C509337:LRAB protein, Leishmania major; D020691:rab GTP-Binding Proteins