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AKAP12 deficiency impairs VEGF‐induced endothelial cell migration and sprouting
Author(s) -
Benz Peter M.,
Ding Yindi,
Stingl Heike,
Loot Annemarieke E.,
Zink Joana,
Wittig Ilka,
Popp Rüdiger,
Fleming Ingrid
Publication year - 2020
Publication title -
acta physiologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.591
H-Index - 116
eISSN - 1748-1716
pISSN - 1748-1708
DOI - 10.1111/apha.13325
Subject(s) - microbiology and biotechnology , angiogenesis , lamellipodium , phosphorylation , scaffold protein , endothelial stem cell , actin cytoskeleton , biology , downregulation and upregulation , chemistry , cell migration , cytoskeleton , signal transduction , cell , cancer research , biochemistry , in vitro , gene
Aim Protein kinase (PK) A anchoring protein (AKAP) 12 is a scaffolding protein that anchors PKA to compartmentalize cyclic AMP signalling. This study assessed the consequences of the downregulation or deletion of AKAP12 on endothelial cell migration and angiogenesis. Methods The consequences of siRNA‐mediated downregulation AKAP12 were studied in primary cultures of human endothelial cells as well as in endothelial cells and retinas from wild‐type versus AKAP12 −/− mice. Molecular interactions were investigated using a combination of immunoprecipitation and mass spectrometry. Results AKAP12 was expressed at low levels in confluent endothelial cells but its expression was increased in actively migrating cells, where it localized to lamellipodia. In the postnatal retina, AKAP12 was expressed by actively migrating tip cells at the angiogenic front, and its deletion resulted in defective extension of the vascular plexus. In migrating endothelial cells, AKAP12 was co‐localized with the PKA type II‐α regulatory subunit as well as multiple key regulators of actin dynamics and actin filament‐based movement; including components of the Arp2/3 complex and the vasodilator‐stimulated phosphoprotein (VASP). Fitting with the evidence of a physical VASP/AKAP12/PKA complex, it was possible to demonstrate that the VEGF‐stimulated and PKA‐dependent phosphorylation of VASP was dependent on AKAP12. Indeed, AKAP12 colocalized with phospho‐Ser157 VASP at the leading edge of migrating endothelial cells. Conclusion The results suggest that compartmentalized AKAP12/PKA signalling mediates VASP phosphorylation at the leading edge of migrating endothelial cells to translate angiogenic stimuli into altered actin dynamics and cell movement.