VINCULIN IS DELIVERED TO A RECYCLING COMPARTMENT AFTER BRADYKININ TREATMENT OF COLLECTING DUCT CELLS

MARQUEZ MG; FERNANDEZ-TOME MC; FAVALE NO; STERIN-SPEZIALE NB

Carlos Paz, Córdoba, Argentina

Congreso; XLIV Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research.; 2008

SAIB

Focal adhesions (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 thecellular 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 phaseendocytosismarker, dextran (Overlap coefficients= R<0.7). By contrast, vinculin colocalized with the marker of recycling endocytic pathway, transferrin receptor (TfR) after BK stimulation (R>0.7). 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.