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Expression of an endocytic‐defective VE‐cadherin mutant cannot restore cell‐cell‐adhesion in the absence p120 in the endothelium
Author(s) -
Garrett Joshua P,
Lowery Anthony M,
Kowalczyk Andrew P,
Vincent Peter A
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.57.12
Subject(s) - endocytosis , adherens junction , microbiology and biotechnology , ve cadherin , cadherin , biology , endocytic cycle , cell adhesion , endothelial stem cell , endothelium , cell , biochemistry , endocrinology , in vitro
Vascular endothelial cadherin (VE‐cad) is an Adherens Junction (AJ) transmembrane protein found at the cell‐cell junction in endothelial cells (EC) which participates in cell‐cell adhesion. The juxtamembrane domain of VE‐cad binds to p120 to regulate the levels of VE‐cad. Previously, we found that depletion of p120 using shRNA results in a decrease in the level of VE‐cad and a decrease in monolayer integrity as assessed by trans‐endothelial electrical resistance (TEER). Re‐expression of p120 can restore both the decrease in TEER and VE‐cad levels. In contrast, re‐expression of VE‐cad to normal levels in the absence of p120 will not rescue TEER even though VE‐cad is found at cell‐cell junctions. We hypothesize that re‐expression of VE‐cad does not rescue TEER in the absence of p120 due to an increase in VE‐cad endocytosis. To test this hypothesis, we expressed a VE‐cad mutant (DEE‐VE‐cad) that has limited endocytosis even in absence of p120 binding. Expression of DEE‐VE‐cad, following p120 depletion, was unable to rescue TEER even though the levels of DEE‐VE‐cad were equal to or above levels of endogenous VE‐cad and was localized at the cell‐cell junction. These results indicate that prevention of VE‐cad endocytosis is not the only mechanism by which p120 regulates the formation of a mature AJ in EC monolayers.