IQUIBICEN   23947
INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CIENCIAS EXACTAS Y NATURALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Binding of a tau-like protein of Xenopus laevis to microtubules: a fluorescence correlation Analysis
Autor/es:
JUAN F. ANGIOLINI; DIANA E. WETZLER; CARLA PALLAVICINI; LUCIANA BRUNO; VALERIA LEVI
Lugar:
Tucuman
Reunión:
Congreso; XLI Reunión Anual de la Sociedad Argentina de Biofísica; 2012
Institución organizadora:
SAB
Resumen:
Microtubules are
decorated with a family of proteins called MAPs (microtubule associated
proteins) that carry out a wide range of functions, from stabilizing and
destabilizing microtubules to regulating spacing and mediating interaction of
microtubules with other proteins. Tau protein is one of the most abundant MAPs
in neurons and has a central role in neurodegenerative diseases, such as
Alzheimer's.
Previous works showed that molecular
motors and tau proteins share the same binding site on microtubules suggesting
that tau may affect transport mediated by molecular motors. In this direction,
it has been shown in in vitro experiments that tau interferes with the
binding of kinesin to the microtubule. However, these experiments were done in
conditions far from those observed in cells
In this work we explored the binding of
XTP (a tau-like protein from Xenopus laevis melanophores) to
microtubules and its relevance to transport mediated by molecular motors. We
acquired confocal movies of regions of cells expressing XTP-GFP and tracked in
these movies regions of microtubules to obtain their fluorescence as a function
of time. We could determine the autocorrelation function in different regions
of each microtubule and fitted the resulting data with a model that consider
that fluctuations are due to the binding/unbinding of XTP to the microtubule. We could observe that microtubules do not
bind XTP homogenously showing submicrometer-sized regions with high affinity
for the MAP protein. To further explore the relevance of these regions to the
transport, we generated red-fluorescent endosomes and tracked simultaneously
the binding of XTP to microtubule and the motion of these organelles.