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Distinct Signaling Functions of Rap1 Isoforms in NO Release From Endothelium
Small GTPase Rap1 plays a prominent role in endothelial cell (EC) homeostasis by promoting NO release. Endothelial deletion of the two highly homologous Rap1 isoforms, Rap1A and Rap1B, leads to endothelial dysfunction ex vivo and hypertension in vivo. Mechanistically, we showed that Rap1B promotes N...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Frontiers Media S.A.
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8247587/ https://www.ncbi.nlm.nih.gov/pubmed/34222255 http://dx.doi.org/10.3389/fcell.2021.687598 |
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author | Kosuru, Ramoji Singh, Bandana Lakshmikanthan, Sribalaji Nishijima, Yoshinori Vasquez-Vivar, Jeannette Zhang, David X. Chrzanowska, Magdalena |
author_facet | Kosuru, Ramoji Singh, Bandana Lakshmikanthan, Sribalaji Nishijima, Yoshinori Vasquez-Vivar, Jeannette Zhang, David X. Chrzanowska, Magdalena |
author_sort | Kosuru, Ramoji |
collection | PubMed |
description | Small GTPase Rap1 plays a prominent role in endothelial cell (EC) homeostasis by promoting NO release. Endothelial deletion of the two highly homologous Rap1 isoforms, Rap1A and Rap1B, leads to endothelial dysfunction ex vivo and hypertension in vivo. Mechanistically, we showed that Rap1B promotes NO release in response to shear flow by promoting mechanosensing complex formation involving VEGFR2 and Akt activation. However, the specific contribution of the Rap1A isoform to NO release and the underlying molecular mechanisms through which the two Rap1 isoforms control endothelial function are unknown. Here, we demonstrate that endothelial dysfunction resulting from knockout of both Rap1A and Rap1B isoforms is ameliorated by exogenous L-Arg administration to rescue NO-dependent vasorelaxation and blood pressure. We confirmed that Rap1B is rapidly activated in response to agonists that trigger eNOS activation, and its deletion in ECs attenuates eNOS activation, as detected by decreased Ser1177 phosphorylation. Somewhat surprising was the finding that EC deletion of Rap1A does not lead to impaired agonist-induced vasorelaxation ex vivo. Mechanistically, the deletion of Rap1A led to elevated eNOS phosphorylation both at the inhibitory, T495, and the activating Ser1177 residues. These findings indicate that the two Rap1 isoforms act via distinct signaling pathways: while Rap1B directly positively regulates eNOS activation, Rap1A prevents negative regulation of eNOS. Notably, the combined deficiency of Rap1A and Rap1B has a severe effect on eNOS activity and NO release with an in vivo impact on endothelial function and vascular homeostasis. |
format | Online Article Text |
id | pubmed-8247587 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-82475872021-07-02 Distinct Signaling Functions of Rap1 Isoforms in NO Release From Endothelium Kosuru, Ramoji Singh, Bandana Lakshmikanthan, Sribalaji Nishijima, Yoshinori Vasquez-Vivar, Jeannette Zhang, David X. Chrzanowska, Magdalena Front Cell Dev Biol Cell and Developmental Biology Small GTPase Rap1 plays a prominent role in endothelial cell (EC) homeostasis by promoting NO release. Endothelial deletion of the two highly homologous Rap1 isoforms, Rap1A and Rap1B, leads to endothelial dysfunction ex vivo and hypertension in vivo. Mechanistically, we showed that Rap1B promotes NO release in response to shear flow by promoting mechanosensing complex formation involving VEGFR2 and Akt activation. However, the specific contribution of the Rap1A isoform to NO release and the underlying molecular mechanisms through which the two Rap1 isoforms control endothelial function are unknown. Here, we demonstrate that endothelial dysfunction resulting from knockout of both Rap1A and Rap1B isoforms is ameliorated by exogenous L-Arg administration to rescue NO-dependent vasorelaxation and blood pressure. We confirmed that Rap1B is rapidly activated in response to agonists that trigger eNOS activation, and its deletion in ECs attenuates eNOS activation, as detected by decreased Ser1177 phosphorylation. Somewhat surprising was the finding that EC deletion of Rap1A does not lead to impaired agonist-induced vasorelaxation ex vivo. Mechanistically, the deletion of Rap1A led to elevated eNOS phosphorylation both at the inhibitory, T495, and the activating Ser1177 residues. These findings indicate that the two Rap1 isoforms act via distinct signaling pathways: while Rap1B directly positively regulates eNOS activation, Rap1A prevents negative regulation of eNOS. Notably, the combined deficiency of Rap1A and Rap1B has a severe effect on eNOS activity and NO release with an in vivo impact on endothelial function and vascular homeostasis. Frontiers Media S.A. 2021-06-17 /pmc/articles/PMC8247587/ /pubmed/34222255 http://dx.doi.org/10.3389/fcell.2021.687598 Text en Copyright © 2021 Kosuru, Singh, Lakshmikanthan, Nishijima, Vasquez-Vivar, Zhang and Chrzanowska. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Cell and Developmental Biology Kosuru, Ramoji Singh, Bandana Lakshmikanthan, Sribalaji Nishijima, Yoshinori Vasquez-Vivar, Jeannette Zhang, David X. Chrzanowska, Magdalena Distinct Signaling Functions of Rap1 Isoforms in NO Release From Endothelium |
title | Distinct Signaling Functions of Rap1 Isoforms in NO Release From Endothelium |
title_full | Distinct Signaling Functions of Rap1 Isoforms in NO Release From Endothelium |
title_fullStr | Distinct Signaling Functions of Rap1 Isoforms in NO Release From Endothelium |
title_full_unstemmed | Distinct Signaling Functions of Rap1 Isoforms in NO Release From Endothelium |
title_short | Distinct Signaling Functions of Rap1 Isoforms in NO Release From Endothelium |
title_sort | distinct signaling functions of rap1 isoforms in no release from endothelium |
topic | Cell and Developmental Biology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8247587/ https://www.ncbi.nlm.nih.gov/pubmed/34222255 http://dx.doi.org/10.3389/fcell.2021.687598 |
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