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Role of AKAP‐mediated PKA compartmentalization for endothelial barrier maintenance
Author(s) -
Radeva Mariya Y.,
Spindler Volker,
Waschke Jens
Publication year - 2011
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.25.1_supplement.817.2
Maintenance of endothelial barrier is mediated by cAMP‐dependent signaling pathways which at least in part involve protein kinase A (PKA). Tight regulation of PKA function can be achieved by discrete compartmentalization of the enzyme via physical interaction with A‐kinase anchoring proteins (AKAPs). By using a cell‐permeable synthetic peptide (TAT‐AKAPis) designed to competitively inhibit PKA‐AKAP interaction, we investigated the importance of AKAPs for cAMP‐dependent endothelial barrier maintenance in cultured human microvascular endothelium. Transendothelial electrical resistance measurements showed that TAT‐AKAPis destabilized endothelial barrier properties whereas increased cAMP levels in response to forskolin/rolipram (F/R) have a protective effect. Moreover, pretreatment with the peptide completely abolished the barrier stabilizing effect of F/R. Immunofluorescence analysis revealed that TAT‐AKAPis induced adherens junction reorganization characterized by an interdigitated distribution of VE‐cadherin at the cell membrane combined with rearrangement of the actin cytoskeleton. In parallel to a partial loss of PKA, membrane staining of Rac1 and IQGAP1 were also reduced. These results indicate that AKAP‐mediated PKA subcellular compartmentalization has a key role in maintenance of endothelial barrier properties. DFG SFB688/TPA4.