Rab GTPases regulate endothelial cell protein C receptor-mediated endocytosis and trafficking of factor VIIa.

Recent studies have established that factor VIIa (FVIIa) binds to the endothelial cell protein C receptor (EPCR). FVIIa binding to EPCR may promote the endocytosis of this receptor/ligand complex. Rab GTPases are known to play a crucial role in the endocytic and exocytic pathways of receptors or rec...

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Main Authors: Ramesh C Nayak, Shiva Keshava, Charles T Esmon, Usha R Pendurthi, L Vijaya Mohan Rao
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3598704?pdf=render
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author Ramesh C Nayak
Shiva Keshava
Charles T Esmon
Usha R Pendurthi
L Vijaya Mohan Rao
author_facet Ramesh C Nayak
Shiva Keshava
Charles T Esmon
Usha R Pendurthi
L Vijaya Mohan Rao
author_sort Ramesh C Nayak
collection DOAJ
description Recent studies have established that factor VIIa (FVIIa) binds to the endothelial cell protein C receptor (EPCR). FVIIa binding to EPCR may promote the endocytosis of this receptor/ligand complex. Rab GTPases are known to play a crucial role in the endocytic and exocytic pathways of receptors or receptor/ligand complexes. The present study was undertaken to investigate the role of Rab GTPases in the intracellular trafficking of EPCR and FVIIa. CHO-EPCR cells and human umbilical vein endothelial cells (HUVEC) were transduced with recombinant adenoviral vectors to express wild-type, constitutively active, or dominant negative mutant of various Rab GTPases. Cells were exposed to FVIIa conjugated with AF488 fluorescent probe (AF488-FVIIa), and intracellular trafficking of FVIIa, EPCR, and Rab proteins was evaluated by immunofluorescence confocal microscopy. In cells expressing wild-type or constitutively active Rab4A, internalized AF488-FVIIa accumulated in early/sorting endosomes and its entry into the recycling endosomal compartment (REC) was inhibited. Expression of constitutively active Rab5A induced large endosomal structures beneath the plasma membrane where EPCR and FVIIa accumulated. Dominant negative Rab5A inhibited the endocytosis of EPCR-FVIIa. Expression of constitutively active Rab11 resulted in retention of accumulated AF488-FVIIa in the REC, whereas expression of a dominant negative form of Rab11 led to accumulation of internalized FVIIa in the cytoplasm and prevented entry of internalized FVIIa into the REC. Expression of dominant negative Rab11 also inhibited the transport of FVIIa across the endothelium. Overall our data show that Rab GTPases regulate the internalization and intracellular trafficking of EPCR-FVIIa.
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spelling doaj.art-603dc7fe8f7d4d809d17243daea1721c2022-12-22T00:29:17ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0183e5930410.1371/journal.pone.0059304Rab GTPases regulate endothelial cell protein C receptor-mediated endocytosis and trafficking of factor VIIa.Ramesh C NayakShiva KeshavaCharles T EsmonUsha R PendurthiL Vijaya Mohan RaoRecent studies have established that factor VIIa (FVIIa) binds to the endothelial cell protein C receptor (EPCR). FVIIa binding to EPCR may promote the endocytosis of this receptor/ligand complex. Rab GTPases are known to play a crucial role in the endocytic and exocytic pathways of receptors or receptor/ligand complexes. The present study was undertaken to investigate the role of Rab GTPases in the intracellular trafficking of EPCR and FVIIa. CHO-EPCR cells and human umbilical vein endothelial cells (HUVEC) were transduced with recombinant adenoviral vectors to express wild-type, constitutively active, or dominant negative mutant of various Rab GTPases. Cells were exposed to FVIIa conjugated with AF488 fluorescent probe (AF488-FVIIa), and intracellular trafficking of FVIIa, EPCR, and Rab proteins was evaluated by immunofluorescence confocal microscopy. In cells expressing wild-type or constitutively active Rab4A, internalized AF488-FVIIa accumulated in early/sorting endosomes and its entry into the recycling endosomal compartment (REC) was inhibited. Expression of constitutively active Rab5A induced large endosomal structures beneath the plasma membrane where EPCR and FVIIa accumulated. Dominant negative Rab5A inhibited the endocytosis of EPCR-FVIIa. Expression of constitutively active Rab11 resulted in retention of accumulated AF488-FVIIa in the REC, whereas expression of a dominant negative form of Rab11 led to accumulation of internalized FVIIa in the cytoplasm and prevented entry of internalized FVIIa into the REC. Expression of dominant negative Rab11 also inhibited the transport of FVIIa across the endothelium. Overall our data show that Rab GTPases regulate the internalization and intracellular trafficking of EPCR-FVIIa.http://europepmc.org/articles/PMC3598704?pdf=render
spellingShingle Ramesh C Nayak
Shiva Keshava
Charles T Esmon
Usha R Pendurthi
L Vijaya Mohan Rao
Rab GTPases regulate endothelial cell protein C receptor-mediated endocytosis and trafficking of factor VIIa.
PLoS ONE
title Rab GTPases regulate endothelial cell protein C receptor-mediated endocytosis and trafficking of factor VIIa.
title_full Rab GTPases regulate endothelial cell protein C receptor-mediated endocytosis and trafficking of factor VIIa.
title_fullStr Rab GTPases regulate endothelial cell protein C receptor-mediated endocytosis and trafficking of factor VIIa.
title_full_unstemmed Rab GTPases regulate endothelial cell protein C receptor-mediated endocytosis and trafficking of factor VIIa.
title_short Rab GTPases regulate endothelial cell protein C receptor-mediated endocytosis and trafficking of factor VIIa.
title_sort rab gtpases regulate endothelial cell protein c receptor mediated endocytosis and trafficking of factor viia
url http://europepmc.org/articles/PMC3598704?pdf=render
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