|
|
|
|
Vol. 17, Issue 2, 966-976, February 2006
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Department of Structural Analysis, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
Submitted July 19, 2005;
Revised November 28, 2005;
Accepted November 29, 2005
Monitoring Editor: Martin A. Schwartz
Rap1 is a small GTPase that regulates adherens junction maturation. It remains elusive how Rap1 is activated upon cell-cell contact. We demonstrate for the first time that Rap1 is activated upon homophilic engagement of vascular endothelial cadherin (VE-cadherin) at the cell-cell contacts in living cells and that MAGI-1 is required for VE-cadherin-dependent Rap1 activation. We found that MAGI-1 localized to cell-cell contacts presumably by associating with
-catenin and that MAGI-1 bound to a guanine nucleotide exchange factor for Rap1, PDZ-GEF1. Depletion of MAGI-1 suppressed the cell-cell contact-induced Rap1 activation and the VE-cadherin-mediated cell-cell adhesion after Ca2+ switch. In addition, relocation of vinculin from cell-extracellular matrix contacts to cell-cell contacts after the Ca2+ switch was inhibited in MAGI-1-depleted cells. Furthermore, inactivation of Rap1 by overexpression of Rap1GAPII impaired the VE-cadherin-dependent cell adhesion. Collectively, MAGI-1 is important for VE-cadherin-dependent Rap1 activation upon cell-cell contact. In addition, once activated, Rap1 upon cell-cell contacts positively regulate the adherens junction formation by relocating vinculin that supports VE-cadherin-based cell adhesion.
Abbreviations used: AJ, adherens junction; CFP, cyan fluorescent protein; ECM, extracellular matrix; EGFP, enhanced green fluorescent protein; FRET, fluorescence resonance energy transfer; GEF, guanine nucleotide exchange factor; GAP, GTPase activating protein; HAEC, human aortic endothelial cell; HUVEC, human umbilical vascular endothelial cell; JAM, junctional adhesion molecule; MAGI-1, MAGUK with inverted domain structure-1; GFP, green fluorescent protein; PBS, phosphate-buffered saline; PDZ, PSD95/DiscLarge/ZO-1; PECAM-1, platelet and endothelial cell adhesion molecule-1; siRNAs, small interfering RNAs; TJ, tight junction; VE-cadherin, vascular endothelial cadherin; VEC-Fc, recombinant VE-cadherin ectodomain-Fc chimera; YFP, yellow fluorescent protein.
![]()
The online version of this article contains supplemental material at MBC Online (http://www.molbiolcell.org).
Address correspondence to: Naoki Mochizuki (nmochizu{at}ri.ncvc.go.jp).
This article has been cited by other articles:
![]() |
E. Dejana, F. Orsenigo, and M. G. Lampugnani The role of adherens junctions and VE-cadherin in the control of vascular permeability J. Cell Sci., July 1, 2008; 121(13): 2115 - 2122. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. D. Mruk, B. Silvestrini, and C. Y. Cheng Anchoring Junctions As Drug Targets: Role in Contraceptive Development Pharmacol. Rev., June 1, 2008; 60(2): 146 - 180. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Vestweber VE-Cadherin: The Major Endothelial Adhesion Molecule Controlling Cellular Junctions and Blood Vessel Formation Arterioscler. Thromb. Vasc. Biol., February 1, 2008; 28(2): 223 - 232. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. E. Zemljic-Harpf, J. C. Miller, S. A. Henderson, A. T. Wright, A. M. Manso, L. Elsherif, N. D. Dalton, A. K. Thor, G. A. Perkins, A. D. McCulloch, et al. Cardiac-Myocyte-Specific Excision of the Vinculin Gene Disrupts Cellular Junctions, Causing Sudden Death or Dilated Cardiomyopathy Mol. Cell. Biol., November 1, 2007; 27(21): 7522 - 7537. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Lorenowicz, M. Fernandez-Borja, and P. L. Hordijk cAMP Signaling in Leukocyte Transendothelial Migration Arterioscler. Thromb. Vasc. Biol., May 1, 2007; 27(5): 1014 - 1022. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Aivatiadou, E. Mattei, M. Ceriani, L. Tilia, and G. Berruti Impaired Fertility and Spermiogenetic Disorders with Loss of Cell Adhesion in Male Mice Expressing an Interfering Rap1 Mutant Mol. Biol. Cell, April 1, 2007; 18(4): 1530 - 1542. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Shasby Cell-cell adhesion in lung endothelium Am J Physiol Lung Cell Mol Physiol, March 1, 2007; 292(3): L593 - L607. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. R. H. Kooistra, N. Dube, and J. L. Bos Rap1: a key regulator in cell-cell junction formation J. Cell Sci., January 1, 2007; 120(1): 17 - 22. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Kawata, J. Iida, M. Ikeda, Y. Sato, H. Mori, A. Kansaku, K. Sumita, N. Fujiwara, C. Rokukawa, M. Hamano, et al. CIN85 Is Localized at Synapses and Forms a Complex with S-SCAM via Dendrin. J. Biochem., May 1, 2006; 139(5): 931 - 939. [Abstract] [Full Text] [PDF] |
||||