biostudies-literatureUnknown185(4)Winderlich MVascular endothelial protein tyrosine phosphatase (VE-PTP) is an endothelial-specific receptor-type tyrosine phosphatase that associates with Tie-2 and VE-cadherin. VE-PTP gene disruption leads to embryonic lethality, vascular remodeling defects, and enlargement of vascular structures in extraembryonic tissues. We show here that antibodies against the extracellular part of VE-PTP mimic the effects of VE-PTP gene disruption exemplified by vessel enlargement in allantois explants. These effects require the presence of the angiopoietin receptor Tie-2. Analyzing the mechanism we found that anti-VE-PTP antibodies trigger endocytosis and selectively affect Tie-2-associated, but not VE-cadherin-associated VE-PTP. Dissociation of VE-PTP triggers the activation of Tie-2, leading to enhanced endotheThe Journal of cell biology657-71https://www.ebi.ac.uk/biostudies/studies/S-EPMC2711575biostudies-literatureVE-PTP controls blood vessel development by balancing Tie-2 activity.PMC2711575Winderlich MVestweber DCagna GKeller LKamenyeva OKiefer FBroermann ADeutsch UNottebaum AFfalseVE-PTP controls blood vessel development by balancing Tie-2 activity.Vascular endothelial protein tyrosine phosphatase (VE-PTP) is an endothelial-specific receptor-type tyrosine phosphatase that associates with Tie-2 and VE-cadherin. VE-PTP gene disruption leads to embryonic lethality, vascular remodeling defects, and enlargement of vascular structures in extraembryonic tissues. We show here that antibodies against the extracellular part of VE-PTP mimic the effects of VE-PTP gene disruption exemplified by vessel enlargement in allantois explants. These effects require the presence of the angiopoietin receptor Tie-2. Analyzing the mechanism we found that anti-VE-PTP antibodies trigger endocytosis and selectively affect Tie-2-associated, but not VE-cadherin-associated VE-PTP. Dissociation of VE-PTP triggers the activation of Tie-2, leading to enhanced endothe2009-01-01T00:00:00Z2009 May2025-04-22T15:15:27.418Z2019-06-06T21:31:29ZS-EPMC27115751945127410.1083/jcb.200811159