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A mechanism of Rap1-induced stabilization of endothelial cell–cell junctions

Activation of Rap1 small GTPases stabilizes cell–cell junctions, and this activity requires Krev Interaction Trapped gene 1 (KRIT1). Loss of KRIT1 disrupts cardiovascular development and causes autosomal dominant familial cerebral cavernous malformations. Here we report that native KRIT1 protein bin...

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Autores principales: Liu, Jian J., Stockton, Rebecca A., Gingras, Alexandre R., Ablooglu, Ararat J., Han, Jaewon, Bobkov, Andrey A., Ginsberg, Mark H.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The American Society for Cell Biology 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3135476/
https://www.ncbi.nlm.nih.gov/pubmed/21633110
http://dx.doi.org/10.1091/mbc.E11-02-0157
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author Liu, Jian J.
Stockton, Rebecca A.
Gingras, Alexandre R.
Ablooglu, Ararat J.
Han, Jaewon
Bobkov, Andrey A.
Ginsberg, Mark H.
author_facet Liu, Jian J.
Stockton, Rebecca A.
Gingras, Alexandre R.
Ablooglu, Ararat J.
Han, Jaewon
Bobkov, Andrey A.
Ginsberg, Mark H.
author_sort Liu, Jian J.
collection PubMed
description Activation of Rap1 small GTPases stabilizes cell–cell junctions, and this activity requires Krev Interaction Trapped gene 1 (KRIT1). Loss of KRIT1 disrupts cardiovascular development and causes autosomal dominant familial cerebral cavernous malformations. Here we report that native KRIT1 protein binds the effector loop of Rap1A but not H-Ras in a GTP-dependent manner, establishing that it is an authentic Rap1-specific effector. By modeling the KRIT1–Rap1 interface we designed a well-folded KRIT1 mutant that exhibited a ∼40-fold-reduced affinity for Rap1A and maintained other KRIT1-binding functions. Direct binding of KRIT1 to Rap1 stabilized endothelial cell–cell junctions in vitro and was required for cardiovascular development in vivo. Mechanistically, Rap1 binding released KRIT1 from microtubules, enabling it to locate to cell–cell junctions, where it suppressed Rho kinase signaling and stabilized the junctions. These studies establish that the direct physical interaction of Rap1 with KRIT1 enables the translocation of microtubule-sequestered KRIT1 to junctions, thereby supporting junctional integrity and cardiovascular development.
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spelling pubmed-31354762011-09-30 A mechanism of Rap1-induced stabilization of endothelial cell–cell junctions Liu, Jian J. Stockton, Rebecca A. Gingras, Alexandre R. Ablooglu, Ararat J. Han, Jaewon Bobkov, Andrey A. Ginsberg, Mark H. Mol Biol Cell Articles Activation of Rap1 small GTPases stabilizes cell–cell junctions, and this activity requires Krev Interaction Trapped gene 1 (KRIT1). Loss of KRIT1 disrupts cardiovascular development and causes autosomal dominant familial cerebral cavernous malformations. Here we report that native KRIT1 protein binds the effector loop of Rap1A but not H-Ras in a GTP-dependent manner, establishing that it is an authentic Rap1-specific effector. By modeling the KRIT1–Rap1 interface we designed a well-folded KRIT1 mutant that exhibited a ∼40-fold-reduced affinity for Rap1A and maintained other KRIT1-binding functions. Direct binding of KRIT1 to Rap1 stabilized endothelial cell–cell junctions in vitro and was required for cardiovascular development in vivo. Mechanistically, Rap1 binding released KRIT1 from microtubules, enabling it to locate to cell–cell junctions, where it suppressed Rho kinase signaling and stabilized the junctions. These studies establish that the direct physical interaction of Rap1 with KRIT1 enables the translocation of microtubule-sequestered KRIT1 to junctions, thereby supporting junctional integrity and cardiovascular development. The American Society for Cell Biology 2011-07-15 /pmc/articles/PMC3135476/ /pubmed/21633110 http://dx.doi.org/10.1091/mbc.E11-02-0157 Text en © 2011 Liu et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). “ASCB®,” “The American Society for Cell Biology®,” and “Molecular Biology of the Cell®” are registered trademarks of The American Society of Cell Biology.
spellingShingle Articles
Liu, Jian J.
Stockton, Rebecca A.
Gingras, Alexandre R.
Ablooglu, Ararat J.
Han, Jaewon
Bobkov, Andrey A.
Ginsberg, Mark H.
A mechanism of Rap1-induced stabilization of endothelial cell–cell junctions
title A mechanism of Rap1-induced stabilization of endothelial cell–cell junctions
title_full A mechanism of Rap1-induced stabilization of endothelial cell–cell junctions
title_fullStr A mechanism of Rap1-induced stabilization of endothelial cell–cell junctions
title_full_unstemmed A mechanism of Rap1-induced stabilization of endothelial cell–cell junctions
title_short A mechanism of Rap1-induced stabilization of endothelial cell–cell junctions
title_sort mechanism of rap1-induced stabilization of endothelial cell–cell junctions
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3135476/
https://www.ncbi.nlm.nih.gov/pubmed/21633110
http://dx.doi.org/10.1091/mbc.E11-02-0157
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