Inhibition of Trypanosoma brucei arginine kinase gene expression by RNA interference.

PEREIRA, CLAUDIO; GINGER, MICHAEL; BOUVIER, LEÓN ALBERTO; TORRES, HECTOR; GULL, KEITH

San Carlos de Bariloche, Argentina

Congreso; XXXIX Reunion anual Sociedad Argentina de Investigacion Bioquimica y Biologia Molecular (SAIB).; 2003

Arginine kinase catalyzes the reversible transphosphorylation between ADP and phosphoarginine, which is involved in temporal and spatial ATP buffering. The molecular and biochemical characterization of arginine kinase in Trypanosoma cruzi has been reported by our laboratory. Here, we report that three distinct arginine kinase genes are expressed by the African trypanosome T. brucei. The three genes are clustered together in chromosome IX and show a high degree of identity with one another, suggesting that the family has evolved following a tandem duplication event. The three proteins differ only in the nature of their N and C termini raising the possibility that each gene is targeted to a different cellular site or provide different cellular functions. Interestingly, although the expression of all three genes in procyclic trypanosomes can be efficiently silenced by RNAi, using a 400 bp fragment common to all three genes, our initial phenotype studies show there is no growth phenotype in the RNA knockdown mutants. Nor do these mutants show an increased sensitivity towards sodium azide, an inhibitor of the classical respiratory chain, or SHAM which is an inhibitor of trypanosome alternative oxidase.