Identification of a new developmentally regulated Leishmania major large RAB GTPase.

Mehdi Chenik (1) , Noura Chaabouni (1) , Yosser Ben Achour-Chenik (1) , Meriem Ouakad (1) , Inès Lakhal-Naouar (1) , Hechmi Louzir (1) , Koussay Dellagi (1)

1 LVGM - Laboratoire d'Immunopathologie, Vaccinologie et Génétique Moléculaire

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.

Mots clés: Leishmania; GTPase; RAB-like; Gene expression; Intracellular transport; Endocytosis; Exocytosis

Domaines: Médecine humaine et pathologie

Mehdi Chenik, Noura Chaabouni, Yosser Ben Achour-Chenik, Meriem Ouakad, Inès Lakhal-Naouar, et al.. Identification of a new developmentally regulated Leishmania major large RAB GTPase.. Biochemical and Biophysical Research Communications, 2006, 341 (2), pp.541-8. ⟨10.1016/j.bbrc.2006.01.005⟩. ⟨hal-01974057⟩