RNAi analysis of the SCF complex in Trypanosoma cruzi

ROJAS F; ERBEN E.D.,; BOYNAK N; TÉLLEZ-IÑÓN M. T.

Rosario, Argentina

Congreso; XLII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology; 2006

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Regulated protein degradation has emerged as a key recurring theme in multiple aspects of cell-cycle regulation. The importance of this process appears evident in the organization of the cell division cycle triggered by the destruction of key regulatory proteins. Many proteins are targeted to the proteasome degradation by a family of E3 ubiquitin-ligases, named SCF complexes, which link substrate proteins to an E2 ubiquitin-conjugating enzyme. Three core proteins compose SCFs: Skp1, Cdc53/Cullin1, Rbx1/ROC1. It has been shown that this complex is a key regulator in the transitions between G1/S, G2/M and in mitotic progression. Querying the Trypanosoma brucei genome database (GeneDB) we have identified the homologues to the human components of the SCF complex. The cell cycle of protozoan parasite T.brucei is a highly coordinated process, which ensures that there is correct replication and segregation of its single organelles: the flagellum, nucleus and kinetoplast. We have used RNA interference to study the involvement of the SCF components in T.brucei cell cycle regulation. Procyclics parasites were analysed for defects in cell cycle progression by assessment of growth and by microscopy to visualise the distribution of organelles and DNA content. In this presentation, the phenotypes observed by knocking down these proteins will be discussed.