Generation of Epithelial Cell Polarity: Roles for Protein Trafficking, Membrane-Cytoskeleton, and E-Cadherin-mediated Cell Adhesion
- R.W. Mays1,
- W.J. Nelson, and
- J.A. Marrs2
This extract was created in the absence of an abstract.
Excerpt
Polarized epithelial cells form barriers between biological compartments and modulate the ionic environment of those compartments by vectorial transport of ions and solutes across the epithelium. These functions are regulated by cell-cell interactions and asymmetric distributions of ion channels and transporters between distinct plasma membrane domains that face different compartments (Aimers and Sterling 1984).
An important problem is to understand mechanisms of protein sorting to different membrane domains that generate and maintain epithelial cell polarity. In general, intracellular protein sorting in the secretory pathway is regulated by vesicles that dock with target membranes and by intrinsic protein signals that target and retain proteins in correct compartments (Nelson 1992; Rodriguez-Boulan and Powell 1992). A fundamental question, however, is how asymmetry on the plasma membrane in polarized cells is generated and then recognized by this intracellular sorting machinery.
In epithelial cells, E-cadherin-mediated cell adhesion provides a positional cue on the cell surface...
