Tight junctions and the molecular basis for regulation of
paracellular permeability.
Anderson, J. M., and C. M. Van Itallie.
Division of Digestive Diseases, Internal Medicine and Cell Biology,
Yale School of Medicine, New Haven CT 06520-8019, USA
APStracts 2:0149G, 1995.
Tight junctions create a regulated paracellular barrier to the
movement of water, solutes and immune cells between both epithelial
and endothelial cells. Recent progress has been made in identifying
the proteins that create this barrier. The transmembrane protein
occludin is an excellent candidate for the sealing protein, and is
bound on the cytoplasmic membrane surface to the proteins ZO-1 and
ZO-2. Functions for ZO-1 and ZO-2 are suggested by their invertebrate
homologs, one of which is a tumor suppressor and another is required
in EGF receptor signalling. Multiple cellular signalling pathways
affect assembly and sealing of junctions. Dynamic regulation of
perijunctional actin has emerged as a unifying hypothesis for
controlling paracellular permeability. Understanding and manipulating
permeability will require a more detailed molecular characterization
of tight junction proteins and in particular a characterization of
how cell signalling regulates their attachment to the perijunctional
cytoskeleton.
Received 18 July 1995; accepted in final form 22 July 1995.
APS Manuscript Number G307-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 July 1995.