Tyrosine phosphorylation of DEP-1/CD148 as a mechanism controlling Src kinase activation, endothelial cell permeability, invasion, and capillary formation.
DEP-1/CD148 is a receptor-like protein tyrosine phosphatase with antiproliferative and tumor-suppressive functions. Interestingly, it also positively regulates Src family kinases in hematopoietic and endothelial cells, where we showed it promotes VE-cadherin-associated Src activation and endothelial cell survival upon VEGF stimulation. However, the molecular mechanism involved and its biologic functions in endothelial cells remain ill-defined. We demonstrate here that DEP-1 is phosphorylated in a Src- and Fyn-dependent manner on Y1311 and Y1320, which bind the Src SH2 domain. This allows DEP-1-catalyzed dephosphorylation of Src inhibitory Y529 and favors the VEGF-induced phosphorylation of Src substrates VE-cadherin and Cortactin. Accordingly, RNA interference (RNAi)-mediated knockdown of DEP-1 or expression of DEP-1 Y1311F/Y1320F impairs Src-dependent biologic responses mediated by VEGF including permeability, invasion, and branching capillary formation. In addition, our work further reveals that above a threshold expression level, DEP-1 can also dephosphorylate Src Y418 and attenuate downstream signaling and biologic responses, consistent with the quiescent behavior of confluent endothelial cells that express the highest levels of endogenous DEP-1. Collectively, our findings identify the VEGF-dependent phosphorylation of DEP-1 as a novel mechanism controlling Src activation, and show this is essential for the proper regulation of permeability and the promotion of the angiogenic response.
Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM) and Institut du Cancer de Montréal, Montréal, QC, Canada.
Kathleen
K
Spring
Catherine
C
Chabot
Simon
S
Langlois
Line
L
Lapointe
Nguyen Thu Ngan
NT
Trinh
Christine
C
Caron
Jagoda K
JK
Hebda
Julie
J
Gavard
Mounib
M
Elchebly
Isabelle
I
Royal
D015703:Antigens, CD / Q000378:metabolism; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism; D002196:Capillaries / Q000378:metabolism*; D002448:Cell Adhesion; D002463:Cell Membrane Permeability; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D051356:Cortactin / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation; D009154:Mutation / Q000235:genetics; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic; D010766:Phosphorylation; D054631:Receptor-Like Protein Tyrosine Phosphatases, Class 3 / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014443:Tyrosine / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism*; D000099152:Cadherin 5
D015703:Antigens, CD; D015820:Cadherins; D051356:Cortactin; D054631:Receptor-Like Protein Tyrosine Phosphatases, Class 3; D014443:Tyrosine; D042461:Vascular Endothelial Growth Factor A; D019061:src-Family Kinases; D000099152:Cadherin 5; C495868:CTTN protein, human; C467484:VEGFA protein, human; C486288:PTPRJ protein, human