Bmx is a downstream Rap1 effector in VEGF-induced endothelial cell activation.
We had previously shown that Rap1 mediates certain of the signaling pathways involved in VEGF-induced endothelial cell migration, although the downstream Rap1 effectors are not known. Towards the goal of identifying those effectors, we utilized a commercially available antibody array filter to identify proteins that either directly interact with Rap1 or interact indirectly through a multi-protein complex. The protocol identified 10 possible Rap1-interacting proteins, including the Bmx non-receptor tyrosine kinase. The conclusion that VEGF treatment leads to a Rap1/Bmx complex was confirmed by an experiment in which cell lysates from VEGF and control cells were immunoprecipitated with Bmx antibodies and Western blotting was done using anti-Rap1 antibodies. VEGF treatment led to the recruitment of Bmx to the CAS scaffolding protein, and inhibition of the Bmx kinase blocked VEGF-induced cell migration. Formation of a Rap1/Bmx complex was not observed in cells transfected with an expression vector for a dominant-negative Rap1, indicating that Bmx is a downstream Rap1 effector in VEGF-induced endothelial cell activation.
Stoletov
Konstantin V
KV
Cardiology Division, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Terman
Bruce I
BI
D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D014471:Umbilical Veins / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*; D020827:rap1 GTP-Binding Proteins / Q000378:metabolism*
D042461:Vascular Endothelial Growth Factor A; D020827:rap1 GTP-Binding Proteins