INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
BIOCHEMICAL CHARACTERIZATION OF TCCYC6: A PROTEIN WITH CYCLIN HOMOLOGY FROM TRYPANOSOMA CRUZI
Autor/es:
AGOSTINA DI RENZO; MARÍA TERESA TELLEZ-IÑÓN; MARC LAVERRIERE; SERGIO SCHENKMAN; MARIANA POTENZA
Lugar:
Mar del Plata, Argentina
Reunión:
Congreso; X Congreso de Protozoología y Enfermedades Parasitarias; 2014
Institución organizadora:
Sociedad Argentina de Protozoología
Resumen:
The cell cycle is a highly regulated process that requires Cyclin-Dependent Kinases (CDKs) in association with cyclins and other factors to activate or inactivate biochemical pathways that leads to proper duplication and segregation into new daughter cells. Which are these regulators controlling the cell cycle in Trypanosoma cruzi, a pathogen parasite that alters between proliferative and non dividing forms, is still poorly understood and deserves further study. The genome of T. cruzi codify for ten sequences with cyclin homology (TcCYC2 to TcCYC11), three of which were characterized at functional level by our group (TcCYC2, TcCCY4 and TcCYC5). In order to further understand the role of the cyclin family in the cell cycle control of this parasite, a sequence with similarity to mitotic cyclins (TcCYC6), was studied. For this purpose, we first raised polyclonal antibodies against a N-terminal peptide of TcCYC6 protein. This antibody was unable to detect the endogenous expression of TcCYC6 in epimastigotes either by western blot or immunofluorescence microscopy. However, it was possible to isolate the TcCYC6 messenger RNA, indicating that this gene is processed at least as mature transcript. Then, we cloned the TcCYC6 coding sequence fused to the Influenza hemagglutinin tag HA (TcCYC6-HA), into the inducible expression vector pTcINDEX. Over expression of TcCYC6-HA causes inhibition of epimastigote growth, although the cell cycle pattern of parasite population is not compromise. In agreement with this, studies using immunofluorescence microscopy did not reveal any cell cycle dependent re-localization of this recombinant protein. However, results from treatment with specific inhibitors and affinity chromatography suggested that TcCYC6-HA protein could be degraded by proteasome pathway. Complementation assays suggested that TcCYC6-HA does not complement the G1 cyclin deficiency in yeasts, although other functional experiments are under way.