Rap1 GTPase inhibits leukocyte transmigration by promoting endothelial barrier function.


Journal Article

The passage of leukocytes out of the blood circulation and into tissues is necessary for the normal inflammatory response, but it also occurs inappropriately in many pathological situations. This process is limited by the barrier presented by the junctions between adjacent endothelial cells that line blood vessels. Here we show that activation of the Rap1 GTPase in endothelial cells accelerated de novo assembly of endothelial cell-cell junctions and increased the barrier function of endothelial monolayers. In contrast, depressing Rap1 activity by expressing Rap1GAP led to disassembly of these junctions and increased their permeability. We also demonstrate that endogenous Rap1 was rapidly activated at early stages of junctional assembly, confirming the involvement of Rap1 during junctional assembly. Intriguingly, elevating Rap1 activity selectively within endothelial cells decreased leukocyte transendothelial migration, whereas inhibiting Rap1 activity by expression of Rap1GAP increased leukocyte transendothelial migration, providing physiological relevance to our hypothesis that Rap1 augments barrier function of inter-endothelial cell junctions. Furthermore, these results suggest that Rap1 may be a novel therapeutic target for clinical conditions in which an inappropriate inflammatory response leads to disease.

Full Text

Duke Authors

Cited Authors

  • Wittchen, ES; Worthylake, RA; Kelly, P; Casey, PJ; Quilliam, LA; Burridge, K

Published Date

  • March 25, 2005

Published In

Volume / Issue

  • 280 / 12

Start / End Page

  • 11675 - 11682

PubMed ID

  • 15661741

Pubmed Central ID

  • 15661741

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.M412595200


  • eng

Conference Location

  • United States