The GTPase TcRjl of the human pathogen Trypanosoma cruzi is involved in the cell growth and differentiation.
The protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas Disease, undergoes through a complex life cycle where rounds of cell division and differentiation occur initially in the gut of triatominae vectors and, after transmission, inside of infected cells in vertebrate hosts. Members of the Ras superfamily of GTPases are molecular switches which play pivotal regulatory functions in cell growth and differentiation. We have previously described a novel GTPase in T. cruzi, TcRjl, which belongs to the RJL family of Ras-related GTP binding proteins. Here we show that most of TcRjl protein is found bound to GTP nucleotides and may be locked in this stage. In addition, we show that TcRjl is located close to the kinetoplast, in a region corresponding possibly to flagellar pocket of the parasite and the expression of a dominant-negative TcRjl construct (TcRjlS37N) displays a significative growth phenotype in reduced serum medium. Remarkably, overexpression of TcRjl inhibits differentiation of epimastigotes to trypomastigote forms and promotes the accumulation of intermediate differentiation stages. Our data suggest that TcRjl might play a role in the control of the parasite growth and differentiation.
Laboratório de Parasitologia Molecular, Instituto de Biofísica Carlos Chagas Filho, CCS, UFRJ, Rio de Janeiro, Brazil. wykim@sookmyung.ac.kr
Guilherme Rodrigo Reis Monteiro
GR
dos Santos
José Luciano
JL
Nepomuceno-Silva
Luiz Dione Barbosa
LD
de Melo
José Roberto
JR
Meyer-Fernandes
Didier
D
Salmon
Ricardo Luiz
RL
Azevedo-Pereira
Ulisses Gazos
UG
Lopes
D002454:Cell Differentiation; D049109:Cell Proliferation; D006160:Guanosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D006790:Host-Parasite Interactions; D006801:Humans; D020559:Monomeric GTP-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000166:cytology / Q000201:enzymology / Q000254:growth & development*
D006160:Guanosine Triphosphate; D020559:Monomeric GTP-Binding Proteins