title: Cyclic AMP phosphodiesterase 4D (PDE4D) Tethers EPAC1 in a vascular endothelial cadherin (VE-Cad)-based signaling complex and controls cAMP-mediated vascular permeability.
abstract: Vascular endothelial cell (VEC) permeability is largely dependent on the integrity of vascular endothelial cadherin (VE-cadherin or VE-Cad)-based intercellular adhesions. Activators of protein kinase A (PKA) or of exchange protein activated by cAMP (EPAC) reduce VEC permeability largely by stabilizing VE-Cad-based intercellular adhesions. Currently, little is known concerning the nature and composition of the signaling complexes that allow PKA or EPAC to regulate VE-Cad-based structures and through these actions control permeability. Using pharmacological, biochemical, and cell biological approaches we identified and determined the composition and functionality of a signaling complex that coordinates cAMP-mediated control of VE-Cad-based adhesions and VEC permeability. Thus, we report that PKA, EPAC1, and cyclic nucleotide phosphodiesterase 4D (PDE4D) enzymes integrate into VE-Cad-based signaling complexes in human arterial endothelial cells. Importantly, we show that protein-protein interactions between EPAC1 and PDE4D serve to foster their integration into VE-Cad-based complexes and allow robust local regulation of EPAC1-based stabilization of VE-Cad-based adhesions. Of potential translational importance, we mapped the EPAC1 peptide motif involved in binding PDE4D and show that a cell-permeable variant of this peptide antagonizes EPAC1-PDE4D binding and directly alters VEC permeability. Collectively, our data indicate that PDE4D regulates both the activity and subcellular localization of EPAC1 and identify a novel mechanism for regulated EPAC1 signaling in these cells.
authors: Department of Pathology & Molecular Medicine, Queen’s University, Kingston, Ontario K7L 3N6, Canada.
authors: Sarah N
authors: SN
authors: Rampersad
authors: Jeffrey D
authors: JD
authors: Ovens
authors: Elaine
authors: E
authors: Huston
authors: M Bibiana
authors: MB
authors: Umana
authors: Lindsay S
authors: LS
authors: Wilson
authors: Stuart J
authors: SJ
authors: Netherton
authors: Martin J
authors: MJ
authors: Lynch
authors: George S
authors: GS
authors: Baillie
authors: Miles D
authors: MD
authors: Houslay
authors: Donald H
authors: DH
authors: Maurice
mesh_terms: D020816:Amino Acid Motifs; D015703:Antigens, CD / Q000378:metabolism*; D050197:Atherosclerosis / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism*; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3 / Q000378:metabolism*; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D004730:Endothelium, Vascular / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D006801:Humans; D007365:Intercellular Junctions / Q000378:metabolism; D046911:Macromolecular Substances; D010455:Peptides / Q000737:chemistry; D010539:Permeability; D015398:Signal Transduction; D051176:beta Catenin / Q000378:metabolism; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D015820:Cadherins; D000242:Cyclic AMP; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D020662:Guanine Nucleotide Exchange Factors; D046911:Macromolecular Substances; D010455:Peptides; D051176:beta Catenin; D000099152:Cadherin 5; C116122:RAPGEF3 protein, human; C517376:PDE4D protein, human