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This Article Full Text Full Text (PDF) All Versions of this Article: 297/5/F1181    most recent 00062.2009v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Márquez, M. G. Articles by Sterin-Speziale, N. B. PubMed PubMed Citation Articles by Márquez, M. G. Articles by Sterin-Speziale, N. B.

Bradykinin induces formation of vesicle-like structures containing vinculin and PtdIns(4,5)P₂ in renal papillary collecting duct cells

¹Instituto de Investigaciones en Ciencias de la Salud Humana, Universidad Nacional de La Rioja, La Rioja; and ; ²Cátedra de Biología Celular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires and ; ³Instituto de Química y Físico-Química Biológicas, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina

Submitted February 4, 2009 ; accepted in final form September 10, 2009

Focal adhesions (FAs) are structures of cell attachment to the extracellular matrix. We previously demonstrated that the intrarenal hormone bradykinin (BK) induces the restructuring of FAs in papillary collecting duct cells by dissipation of vinculin, but not talin, from FAs through a mechanism that involves PLCβ activation, and that it also induces actin cytoskeleton reorganization. In the present study we investigated the mechanism by which BK induces the dissipation of vinculin-stained FAs in collecting duct cells. We found that BK induces the internalization of vinculin by a noncaveolar and independent pinocytic pathway and that at least a fraction of this protein is delivered to the recycling endosomal compartment, where it colocalizes with the transferrin receptor. Regarding the reassembly of vinculin-stained FAs, we found that BK induces the formation of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P₂]-enriched vinculin-containing vesicles, which, by following a polarized exocytic route, transport vinculin to the site of FA assembly, an action that depends on actin filaments. The present study, which was carried out with cells that were not genetically manipulated, shows for the first time that BK induces the formation of vesicle-like structures containing vinculin and PtdIns(4,5)P₂, which transport vinculin to the site of FA assembly. Therefore, the modulation of the formation of these vesicle-like structures could be a physiological mechanism through which the cell can reuse the BK-induced internalized vinculin to be delivered for newly forming FAs in renal papillary collecting duct cells.

focal adhesions; renal papillae; recycling compartment