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The intracellular trafficking and distribution of VEGF165
Author(s) -
Guzman-Hernandez Maria Luisa,
Potter Gael,
Kim Yeun J,
Kiss Jozsef Z,
Balla Tamas
Publication year - 2012
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.26.1_supplement.lb159
Subject(s) - microbiology and biotechnology , endoplasmic reticulum , secretion , golgi apparatus , intracellular , exocytosis , secretory pathway , angiogenesis , rab , chemistry , vascular endothelial growth factor , vascular endothelial growth factor a , gtpase , biology , biochemistry , vegf receptors , cancer research
Vascular endothelial growth factor (VEGF) is a major regulator of physiological and pathological angiogenesis. Native VEGF from numerous sources corresponds to VEGF165 isoform. While the functional roles of VEGF165 have been extensively studied, its intracellular trafficking and mode of secretion remain largely unknown. Here, we created VEGF165 fused with GFP to monitor the distribution during its trafficking in COS‐7 or HUVEC cells. In parallel studies, we analyzed the release of VEGF165 into the media using Western blot. We found that VEGF165‐GFP forms dimers and gets glycosylated similarly to wild‐type. The molecule follows the endoplasmic reticulum‐Golgi pathway and GDP‐ and GTP‐locked forms of Sar1 and Arf1 GTPases, completely block VEGF secretion. Less clear is the post‐Golgi trafficking of VEGF. We found that VEGF165 is secreted even at 19 °C and its secretion is stimulated both by Ca2+ increases and PKC activators. Also, a significant fraction of VEGF remains associated with the cell surface in discrete areas. Exocytosis of VEGF165 requires PIP2 at the plasma membrane. Further studies are in progress to find the mechanism by which VEGF is released from the plasma membrane and to clarify the exact intracellular site(s) of proteolytic processing of VEGF165.