INIMEC - CONICET   05467
INSTITUTO DE INVESTIGACION MEDICA MERCEDES Y MARTIN FERREYRA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Conferencia por invitación: Ceramide and the Fas receptor
Autor/es:
CARRER, D. C.; WEIDEMANN, T; RIES, J.; SCHWILLE, P.
Lugar:
Buenos Aires
Reunión:
Conferencia; International Gregorio Weber Conference; 2011
Institución organizadora:
Univ. de Buenos Aires
Resumen:
Upon initial activation of the FasR, sphingomyelin is transformed into ceramide at the plasma membrane. The subsequent generation of changes in the membrane organization is proposed as the driving force for the formation of large clusters or caps of FasR, whose activity results enhanced. However, a proof of an actual difference in the physical properties of FasR-ceramide platforms in relation to the rest of the plasma membrane in a context of apoptosis, which would provide for a mechanism of action for ceramide, is lacking.  In model systems, it has been shown that ceramides induce the formation of ordered domains and membrane-associated proteins lateral enrichment at room temperature and at physiological temperature, the details depending on the specific nature of the fatty acyl chain of the ceramide and of the lipids with which it is mixed [1]. The question still remains on the specific effect of ceramides in actual plasma membranes. In this work we aim at measuring, in cultured human cells, the physical properties of the FasR platforms formed upon initiation of apoptosis as compared to the rest of the plasma membrane. We find for the first time that indeed, the physical properties (in particular, the lipid and protein diffusion coefficients) are different in the FasR platforms as compared to the rest of the membrane, but that this is only true in the first minutes after initiation of apoptosis. The results observed in cells coincide with what is observed by similar measurements in model membrane systems with complex compositions [2].