IIBBA   05544
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE BUENOS AIRES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
A WEE1 HOMOLOGUE FROM TRYPANOSOME BRUCEI
Autor/es:
BOYNAK, N; ROJAS, F; D'ALESSIO, C; RODRIGUEZ, V; GHIRINGHELLI, D; TÉLLEZ-IÑÓN, MT
Lugar:
Tucumán, Argentina
Reunión:
Congreso; XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2009
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular
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 pREP3xTbWee. 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.