INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
“A wee1 homologue from Trypanosoma brucei”
Autor/es:
BOYNAK N.Y., ROJAS F., D´ ALESSIO C, RODRÍGUEZ V., GHIRINGHELLI D, TÉLLEZ- IÑÓN MT.
Lugar:
San Miguel de Tucumán, 10-13 Noviembre, Argentina.
Reunión:
Congreso; XLV Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology (SAIB).; 2009
Institución organizadora:
Sociedad Argentina de Investigacíon en Bioquímica y Biología Molecular, SAIB
Resumen:
Cyclin B-Cdc2 kinase activity is required for triggering entry into mitosis in yeast and mammalian cells. Wee1 is a cdc2-inhibitory kinase that prevents premature activation of the mitotic program phosphorylating the Tyr-15 residue in the ATP domain of cdc2. The proteins that regulate cyclinB-Cdc2 complex at the G2/M transition of the Trypanosome brucei cell cycle are not known. We have recently identified a wee1 orthologue in the T.  brucei genome (TbWee). We evaluated if TbWee is able to rescue the Schizosaccharomyces pombe mutant. S. pombe wee1-50 strain was transformed with either the pREP3x vector alone, pREP3x-S. pombe wee1 or the pREP3x–TbWee. Cells transformed with pREP3x grew normally whereas overexpression of TbWee caused the cells to increase in size indicating partial rescue of the mutant. To further characterize TbWee, we purified TbWee1-His protein from Sf9 insect cells and used the recombinant protein in kinase assays with histone H1 as substrate. Histone phosphorylation wasn´t detected but we observed autophosphorylation of TbWee on tyrosine residues. Using RNAi, we determined the essential role of TbWee for cell cycle progression. Hence TbWee exhibits functional properties that are characteristic of wee kinases.