Vinculin Is Delivered To A Recycling Compartment After Bradykinin Treatment Of Collecting Duct Cells

MARQUEZ MG; MARÍA C. FERNÁNDEZ ; N.O. FAVALE,; NORMA B. STERIN-SPEZIALE

Villa Carlos Paz, Córdoba

Congreso; SAIB; 2008

Focal adhesions (FA) are structures of cell attachment to theextracellular 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 vinculinand PIP2 in the citosol. Now, we performed vinculin pixel intensityprofile analysis from cell edge towards cell center to explore thecellular distribution of these vesicles on cultured rat renal papillarycollecting duct cells treated with BK. After 1 min of BK treatment,vesicles accumulated around the nuclei, and at 5 and 10 min werediffusely distributed in the citosol. Pre-treatmente of cells with aselective BK-B2 antagonist, Hoe 140, avoid the dissipation ofvinculin-stained FA. We observed that vinculin-containing vesiclesdid not colocalize with caveolin-1 nor with the fluid phaseendocytosismarker, dextran (Overlap coefficients= R<0.7). Bycontrast, vinculin colocalized with the marker of recyclingendocytic pathway, transferrin receptor (TfR) after BK stimulation(R>0.7). These observations suggest that BK produces theinternalization of vinculin by its delivering to a recyclingcompartment, located in the perinuclear area. From here, vesiclescontaining vinculin migrate to the cell membrane to allow FArestructuration at 10 min after BK stimulation, when thephysiological condition is restored.