QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online December 20, 2006
doi: 10.1242/10.1242/jcs.03306

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kooistra, M. R. H. Articles by Bos, J. L. Search for Related Content PubMed PubMed Citation Articles by Kooistra, M. R. H. Articles by Bos, J. L.

Rap1: a key regulator in cell-cell junction formation

Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands

View larger version (40K): [in this window] [in a new window]   Fig. 1. Overview of the Rap1 signalling network. Adapted from Bos, 2005 with permission (Bos, 2005). DAG, diacylglycerol; E/V, Ena/Vasp; GPCR, G-protein coupled receptor; PIP3, phosphoinositol-tri-phosphate; PLC, phospholipase C; RTK, receptor tyrosine kinase.

View larger version (32K): [in this window] [in a new window]   Fig. 2. Schematic overview of adherens junctions and tight junctions. , -catenin; AF6, afadin/AF6; AJ, adherens junctions; ß, ß-catenin; JAMs, junctional adhesion molecules; p120, p120catenin; TJ, tight junctions; ZO, zona occludens.

View larger version (88K): [in this window] [in a new window]   Fig. 3. Activation of Rap1 in endothelial cells induces cell-cell junction maturation. Anti-VE-cadherin and F-actin staining of HUVE cells treated for 30 minutes with vehicle or the Epac-specific cAMP analog 007. Stimulation with 007 clearly increased cell-cell junction maturation: the adherens junctions form a smoother line between the cells. Endothelial cell permeability is reduced as a biological consequence of the junction tightening (Bar, 10 µm).

View larger version (27K): [in this window] [in a new window]   Fig. 4. Model for the involvement of Rap1 in cell-cell junction formation. At initial cell-cell contacts, C3G bound to E-cadherin is activated, resulting in Rap1 activation. Upon maturation, C3G is displaced by ß-catenin, which interacts with PDZ-GEF to further activate Rap1. Also, extracellular stimuli, including those that stimulate production of cAMP which activates Epac, induce Rap1 activation.