Reversible acetylation regulates vascular endothelial growth factor receptor-2 activity

Abstract

The tyrosine kinase receptor vascular endothelial growth factor receptor 2 (VEGFR2) is a key regulator of angiogenesis. Here we show that VEGFR2 is acetylated in endothelial cells both at four lysine residues forming a dense cluster in the kinase insert domain and at a single lysine located in the receptor activation loop. These modifications are under dynamic control of the acetyltransferase p300 and two deacetylases HDAC5 and HDAC6. We demonstrate that VEGFR2 acetylation essentially regulates receptor phosphorylation. In particular, VEGFR2 acetylation significantly alters the kinetics of receptor phosphorylation after ligand binding, allowing receptor phosphorylation and intracellular signaling upon prolonged stimulation with VEGF. Molecular dynamics simulations indicate that acetylation of the lysine in the activation loop contributes to the transition to an open active state, in which tyrosine phosphorylation is favored by better exposure of the kinase target residues. These findings indicate that post-translational modification by acetylation is a critical mechanism that directly affects VEGFR2 function.

Epigenetic regulation of RTK signaling

“…It is possible that EGFR-mediated acetylation is one mechanism of acquired resistance to HDAC inhibitors, although further research is necessary to test this hypothesis. Similarly, VEGFR acetylation on four residues by p300 has been shown to promote a favorable structural conformation such that it is subsequently phosphorylated and activated, although it is unknown whether VEGF acetylation is relevant in the context of HDAC inhibitor-mediated resistance[24]. …”

BET Bromodomain Suppression Inhibits VEGF-induced Angiogenesis and Vascular Permeability by Blocking VEGFR2-mediated Activation of PAK1 and eNOS

“…Another possibility is that Brd proteins may mediate “inside-out” signaling from the nucleus to the cytoplasm that regulates VEGF-induced VEGFR2 phosphorylation. However, we did not completely rule out the possibility that Brd proteins might shuttle out of the nucleus and to interact with directly with acetylated VEGFR2 or other acetylated proteins in the cytoplasm to regulate signaling pathways that control VEGFR2 activation in ECs since a recent study shows that VEGFR2 acetylation, under dynamic control of the acetyltransferase p300 and two deacetylases HDAC5 and HDAC6, positively regulates receptor phosphorylation and maintains receptor activity upon prolonged VEGF stimulation 39 . This possibility seems to be little because we did not observe the VEGF-induced translocation of Brd4 from nucleus to cytoplasm, measured by immunofluorescence (data not shown).…”

Cross Talk between NOTCH Signaling and Biomechanics in Human Aortic Valve Disease Pathogenesis

“…In healthy AVICs, treatment with osteogenic media resulted in significant inhibition of both VEGF mRNA and protein expression, while no effect on EDP was observed ( Figure 6 ). Interestingly, while mRNA levels for VEGFA were similar between healthy and diseased AVICs, the basal levels of VEGFA protein in the diseased group were significantly higher as compared to healthy controls [ 69 ], suggesting important pathologic differences between transcriptional and translational regulatory mechanisms of VEGFA [ 70 , 71 ], such as post-translational modification, which impacts receptor function [ 72 ] and therefore warrants further investigation. Further, treatment of diseased cells with osteogenic media resulted in stronger inhibition of VEGFA mRNA and protein expression, as compared to the healthy group.…”