Activator of G-protein signaling 8 (AGS8, also known as FNDC1) is a receptor-independent accessory protein for the Gβγ subunit, which was isolated from rat heart subjected to repetitive transient ischemia with the substantial development of collaterals. Here, we report the role of AGS8 in vessel formation by endothelial cells. Knockdown of AGS8 by small interfering RNA (siRNA) inhibited vascular endothelial growth factor (VEGF)-induced tube formation, as well as VEGF-stimulated cell growth and migration. VEGF stimulated the phosphorylation of the VEGF receptor-2 (VEGFR-2, also known as KDR), ERK1/2 and p38 MAPK; however, knockdown of AGS8 inhibited these signaling events. Signal alterations by AGS8 siRNA were associated with a decrease of cell surface VEGFR-2 and an increase of VEGFR-2 in the cytosol. Endocytosis blockers did not influence the decrease of VEGFR-2 by AGS8 siRNA, suggesting the involvement of AGS8 in VEGFR-2 trafficking to the plasma membrane. VEGFR-2 formed a complex with AGS8 in cells, and a peptide designed to disrupt AGS8-Gβγ interaction inhibited VEGF-induced tube formation. These data suggest a potential role for AGS8-Gβγ in VEGF signal processing. AGS8 might play a key role in tissue adaptation by regulating angiogenic events.
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http://dx.doi.org/10.1242/jcs.181883 | DOI Listing |
Sci Rep
February 2019
Department of Physiology, Aichi Medical University, Nagakute, Japan.
Choroidal neovascularization (CNV) is associated with age-related macular degeneration (AMD), a major cause of vision loss among elderly people. Vascular endothelial cell growth factor (VEGF) is essential for the development and progression of AMD, and VEGF signaling molecules are effective targets for the treatment of AMD. We recently reported that activator of G-protein signaling 8 (AGS8), a receptor-independent Gβγ regulator, is involved in VEGF-induced angiogenesis in cultured endothelial cells (EC); however, the role of AGS8 in CNV is not yet understood.
View Article and Find Full Text PDFExp Cell Res
July 2018
Department of Physiology, Aichi Medical University, Nagakute, Aichi, Japan. Electronic address:
Vascular endothelial growth factor C (VEGFC) and its cognate receptor VEGFR-3 play a key role in lymphangiogenesis. We previously reported that an ischemia-inducible Gβγ signal regulator, activator of G-protein signaling 8 (AGS8), regulated the subcellular distribution of vascular endothelial growth factor receptor-2 (VEGFR-2) and influenced VEGFA-induced signaling in vascular endothelial cells. Here, we report that AGS8 regulates VEGFR-3, which is another subtype of the VEGF receptor family, and mediates VEGFC signaling in human dermal lymphatic endothelial cells (HDLECs).
View Article and Find Full Text PDFPLoS One
August 2016
Research Centre, CRCHUM (Centre hospitalier de l'Université de Montréal), Department of Medicine, Université de Montréal, Montréal, Québec, Canada.
Multiple quantitative trait loci (QTLs) for blood pressure (BP) have been detected in rat models of human polygenic hypertension. Great challenges confronting us include molecular identifications of individual QTLs. We first defined the chromosome region harboring C1QTL1 to a segment of 1.
View Article and Find Full Text PDFJ Cell Sci
March 2016
Department of Physiology, Aichi Medical University, Nagakute, Aichi 480-1195, Japan
Activator of G-protein signaling 8 (AGS8, also known as FNDC1) is a receptor-independent accessory protein for the Gβγ subunit, which was isolated from rat heart subjected to repetitive transient ischemia with the substantial development of collaterals. Here, we report the role of AGS8 in vessel formation by endothelial cells. Knockdown of AGS8 by small interfering RNA (siRNA) inhibited vascular endothelial growth factor (VEGF)-induced tube formation, as well as VEGF-stimulated cell growth and migration.
View Article and Find Full Text PDFMethods Mol Biol
May 2015
Department of Pharmacology, University of Toronto, 1 King's College Circle, Toronto, ON, Canada, M5S 1A8,
The identification and characterization of the genes encoding G protein-coupled receptors (GPCRs) and the proteins necessary for the processes of ligand binding, GPCR activation, inactivation, and receptor trafficking to the membrane are discussed in the context of human genetic disease. In addition to functional GPCR variants, the identification of genetic disruptions affecting proteins necessary to GPCR functions have provided insights into the function of these pathways. Gsα and Gβ subunit polymorphisms have been found to result in complex phenotypes.
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