Vascular endothelial-cadherin stabilizes at cell-cell junctions by anchoring to circumferential actin bundles through alpha- and beta-catenins in cyclic AMP-Epac-Rap1 signal-activated endothelial cells.
Vascular endothelial (VE)-cadherin is a cell-cell adhesion molecule involved in endothelial barrier functions. Previously, we reported that cAMP-Epac-Rap1 signal enhances VE-cadherin-dependent cell adhesion. Here, we further scrutinized how cAMP-Epac-Rap1 pathway promotes stabilization of VE-cadherin at the cell-cell contacts. Forskolin induced circumferential actin bundling and accumulation of VE-cadherin fused with green fluorescence protein (VEC-GFP) on the bundled actin filaments. Fluorescence recovery after photobleaching (FRAP) analyses using VEC-GFP revealed that forskolin stabilizes VE-cadherin at cell-cell contacts. These effects of forskolin were mimicked by an activator for Epac but not by that for protein kinase A. Forskolin-induced both accumulation and stabilization of junctional VEC-GFP was impeded by latrunculin A. VE-cadherin, alpha-catenin, and beta-catenin were dispensable for forskolin-induced circumferential actin bundling, indicating that homophilic VE-cadherin association is not the trigger of actin bundling. Requirement of alpha- and beta-catenins for forskolin-induced stabilization of VE-cadherin on the actin bundles was confirmed by FRAP analyses using VEC-GFP mutants, supporting the classical model that alpha-catenin could potentially link the bundled actin to cadherin. Collectively, circumferential actin bundle formation and subsequent linkage between actin bundles and VE-cadherin through alpha- and beta-catenins are important for the stabilization of VE-cadherin at the cell-cell contacts in cAMP-Epac-Rap1 signal-activated cells.
Noda
Kazuomi
K
Department of Structural Analysis, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan.
Zhang
Jianghui
J
Fukuhara
Shigetomo
S
Kunimoto
Satoshi
S
Yoshimura
Michihiro
M
Mochizuki
Naoki
N
D000199:Actins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000378:metabolism; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D005576:Colforsin / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D036681:Fluorescence Recovery After Photobleaching; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D007365:Intercellular Junctions / Q000378:metabolism*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D053778:Thiazolidines / Q000378:metabolism; D051178:alpha Catenin / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*; D020827:rap1 GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000099152:Cadherin 5
D000199:Actins; D015703:Antigens, CD; D019086:Bridged Bicyclo Compounds, Heterocyclic; D015820:Cadherins; D005576:Colforsin; D000242:Cyclic AMP; D017362:Cyclic AMP Response Element-Binding Protein; D020662:Guanine Nucleotide Exchange Factors; D006160:Guanosine Triphosphate; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; D053778:Thiazolidines; D051178:alpha Catenin; D051176:beta Catenin; D020827:rap1 GTP-Binding Proteins; D000099152:Cadherin 5; C116122:RAPGEF3 protein, human; C037067:latrunculin A