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Angiopoietin like 2, an orphelin ligand, is a potent vasodilator
Author(s) -
Farhat Nada,
ThorinTrescases Nathalie,
Mamarbachi Maya,
Drouin Annick,
Perrault Louis,
Allen Bruce,
Thorin Eric
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.527.4
Subject(s) - chemistry , mapk/erk pathway , receptor , sepharose , transactivation , fusion protein , glutathione , affinity chromatography , microbiology and biotechnology , in vitro , kinase , biochemistry , recombinant dna , biology , transcription factor , gene , enzyme
Angiopoietin‐like 2 (Angptl2) is a member of the angiopoietin family whose function and receptor remain unknown. Our objectives were to identify the Angptl2 receptor and study its physiological role in the vasculature. In vitro , exogenous addition of Angptl2 (1 nM) induced a dilation (73.6% + 8.7 of maximum dilation, n=8) of isolated preconstricted mesenteric arteries from normal C57BL6 mice. An Angptl2‐GST fusion protein was purified from the media of stably transfected HEK 293 cells by affinity chromatography on glutathione Sepharose. To purify the Angptl2 receptor, membranes were prepared from human arterial endothelial cells, solubilized, and incubated with Angptl2‐GST (25 mg), or GST, precoupled to glutathione Sepharose beads. After extensive washing, bound proteins were eluted using Laemmli sample buffer and resolved on SDS‐PAGE. Bands were visualized using Sypro Ruby, excised, and sequenced by mass spectrometry (LC‐MSMS). The identified proteins included the EGF receptor (EGFR). Furthermore, shRNA knock down of Angptl2 in HUVECs was associated with reduced phosphorylation of p38, JNK and ERK MAPKs. In conclusion, Angptl2 is a potent vasodilator whose signaling may involve transactivation of the EGFR and activation of the 3 major MAPK cascades. The Angptl2 receptor remains to be identified.