ERG activity is regulated by endothelial FAK coupling with TRIM25/USP9x in vascular patterning

ABSTRACT: Precise vascular patterning is critical for normal growth and development. The ERG transcription factor drives Delta like ligand 4 (DLL4)/Notch signalling and is thought to act as pivotal regulators of endothelial cell (EC) dynamics and developmental angiogenesis. However, molecular regulation of ERG activity remains obscure. Using a series of EC specific Focal Adhesion Kinase (FAK)-knockout (KO) and point-mutant FAK-knockin mice, we show that loss of ECFAK, its kinase activity or phosphorylation at FAK-Y397, but not FAK-Y861, reduces ERG and DLL4 expression levels together with concomitant aberrations in vascular patterning. Rapid Immunoprecipitation Mass Spectrometry of Endogenous Proteins identified that endothelial nuclear-FAK interacts with the de-ubiquitinase USP9x and the ubiquitin ligase TRIM25 enzymes. Further in silico analysis corroborates that ERG interacts with USP9x and TRIM25. Moreover, ERG levels are reduced in FAKKO ECs via a ubiquitin-mediated post-translational modification programme involving USP9x and TRIM25. Re-expression of ERG in vivo and in vitro rescues the aberrant vessel sprouting defects observed in the absence of ECFAK. Our findings identify ECFAK as a regulator of retinal vascular patterning by controlling ERG protein degradation via TRIM25/USP9x.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Endothelial Cell Of Umbilical Vein

SUBMITTER: Alex von kriegsheim  

LAB HEAD: Alex von Kriegsheim

PROVIDER: PXD033447 | Pride | 2022-07-05

REPOSITORIES: Pride