Vinculin is delivered to a recycling compartment after bradykinin treatment of collecting duct cells

M.GABRIELA MÁRQUEZ; MARÍA DEL CARMEN FERNANDEZ-TOMÉ; FAVALE, NICOLÁS; STERIN-SPEZIALE NORMA B

Carlos Paz, Argentina

Congreso; XLIV REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIONES BIOQUÍMICAS Y DE BIOLOGÍA MOLECULAR (SAIB); 2008

SOCIEDAD ARGENTINA DE INVESTIGACIONES BIOQUÍMICAS Y DE BIOLOGÍA MOLECULAR (SAIB)

FA are structures of cell attachment to the extracellular matrix. Previously, we showed that bradykinin (BK) induces a restructuring of FA by dissipation of vinculin-stained FA, concomitant with the appearance of vesicles containing vinculin and PIP2 in the citosol. Now, we performed vinculin pixel intensity profile analysis from cell edge towards cell center to explore the cellular distribution of these vesicles on cultured rat renal papillary collecting duct cells treated with BK. After 1 min of BK treatment, vesicles accumulated around the nuclei, and at 5 and 10 min were diffusely distributed in the citosol. Pre-treatmente of cells with a selective BK-B2 antagonist, Hoe 140, avoid the dissipation of vinculin-stained FA. We had observed that vinculin-containing vesicles does not colocalize with caveolin-1 and with the fluid phase-endocytosis marker, dextran. Now we found that vinculin colocalizes a marker of recycling endocytic pathway, transferrin receptor (TfR) (overlap coefficients >7) after BK stimulation. These observations suggest that, although we don´t know the fate of vinculin internalization, at least a fraction of vinculin is delivered to a recycling compartment, located in the perinuclear area. From here, vesicles containing vinculin could migrate to the cell membrane to allow FA restructuration at 10 min after BK stimulation, when the physiological condition is restored