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

MARÍA GABRIELA MÁRQUEZ1; MARÍA DEL CARMEN FERNÁNDEZ-TOME; NICOLÁS FAVALE; NORMA STERIN-SPEZIALE

Carlos Paz-Córdoba

Congreso; Reunión Anual de la Sociedad Argentina de Investigaciones en Bio; 2008

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 observed that vinculin-containing vesicles did not colocalize with caveolin-1 nor with the fluid phase-endocytosis marker, dextran. By contrast, vinculin colocalized with the marker of recycling endocytic pathway, transferrin receptor (TfR) (overlap coefficients >7) after BK stimulation. These observations suggest that, BK produces the internalization of vinculin by its delivering to a recycling compartment, located in the perinuclear area. From here, vesicles containing vinculin  migrate to the cell membrane to allow FA restructuration at 10 min after BK stimulation, when the physiological condition is restored.