Differential expression of cell-cell and cell-substratum adhesion
proteins along the kidney nephron.
Piepenhagen, Peter A., and W. James Nelson.
Department of Molecular & Cellular Physiology, Stanford
University School of Medicine, Stanford, CA 94305
APStracts 2:0283C, 1995.
Structural and functional differences among epithelial cells of kidney
nephrons may be regulated by variations in cell-cell and cell
-substratum junctions. Using immunofluorescence microscopy, we
demonstrate that the cadherin-associated proteins [alpha]- and
[beta]-catenin are localized to basal-lateral membranes of cells in
all nephron segments, while plakoglobin, a protein associated with
both classical and desmosomal cadherins, is localized to non
-interdigitated lateral membranes in the distal half of the nephron
where it co-localizes with desmoplakin and cytokeratin K8.
Plakoglobin is also present in capillary endothelial cells where
staining for the other catenins and desmosomal proteins is not
observed. Immunofluorescence for laminin A and [alpha]6-integrin,
proteins which mediate cell-substratum contacts, reveal no
correlations with the other staining patterns observed. These data
indicate that plakoglobin and [beta]-catenin subserve distinct
functions in cell-cell adhesion and suggest that E-cadherin-mediated
contacts generate a basal level of cell-cell adhesion while
desmosomal junctions provide additional strength to cell-cell
contacts in the distal nephron.
Received 27 December 1994; accepted in final form 25 May 1995.
APS Manuscript Number C743-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 July 1995.