IFIBYNE   05513
INSTITUTO DE FISIOLOGIA, BIOLOGIA MOLECULAR Y NEUROCIENCIAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Melatonin and Luzindole antagonize glucocorticoid receptor activity by different mechanisms
Autor/es:
PRESMAN, D.M.; LEVI, V; PECCI A
Lugar:
Los Cocos, Cordoba
Reunión:
Workshop; SISTAM 2010; 2010
Resumen:
The antagonism exerted by the pineal hormone melatonin (MEL)
on the glucocorticoid action has been well established; however, its molecular
determinants remain still unknown. Previously, we had described that MEL
inhibits glucocorticoid receptor (GR) nuclear translocation on mouse
thymocytes, most likely by preventing GR-Hsp90 dissociation. Here, we show that
in baby hamster kidney cells (BHK21), MEL neither affects GR translocation nor
GR nuclear homodimerization, but rather impairs GR interaction with the
transcriptional intermediary factor 2 (TIF2). The use of the Mel 1 receptor
antagonist Luzindole curiously reveals that this molecule not only fails to
block MEL effect but also has potential antiglucocorticoid properties per se.
In fact, Luzindole is able to inhibit glucocorticoid-dependent MMTV-driven gene
expression without affecting GR translocation or GR-TIF2 interaction. Together,
these results reveal that both methoxyindoles antagonize GR activity by
different mechanisms and reveal an unexpected diversity on the mechanisms by
which MEL can block GR action.