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Interactions between pigment epithelium‐derived factor (PEDF) and F 1 /F 0 ATP synthase provide insights into its antiangiogenic mechanism
Author(s) -
Notari Luigi,
Arakaki Naokatu,
Amaral Juan,
Mueller David,
Yergey Alfred,
Becerra S. Patricia
Publication year - 2007
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.21.5.a249-b
Subject(s) - pedf , angiostatin , angiogenesis , atp synthase , biochemistry , protein subunit , biology , chemistry , microbiology and biotechnology , surface plasmon resonance , enzyme , cancer research , gene , materials science , nanoparticle , nanotechnology
PEDF is a potent blocker of angiogenesis. Angiostatin and piceatannol bind and inhibit the F 1 catalytic domain of H + ‐ATP synthase on endothelial cell‐surfaces leading to inhibition of migration and proliferation. Radioligand binding assays showed that bovine retina endothelial cell (BREC) surfaces exhibited saturable and high affinity PEDF binding sites. Affinity chromatography and peptide‐mass fingerprinting revealed a PEDF‐binding protein of ~60‐kDa in bovine retina plasma membranes that matched to F 1 ‐ATP synthase β subunit. The PEDF‐binding components in human microvascular endothelial cell (HMVEC) membranes bound to ATP synthase β subunit antibodies in surface plasmon resonance (SPR) and western assays. Direct binding to purified yeast F 1 showed PEDF binding affinities similar to those with intact cells. PEDF efficiently competed with angiostatin for F 1 binding. To determine whether the mechanism by which PEDF inhibits angiogenesis involves ATP synthesis inhibition, we examined the extracellular ATP synthesis activity of HMVECs in the presence of PEDF. HMVECs produced ATP extracellularly, and PEDF significantly inhibited this activity, suggesting a direct interaction of PEDF with ATP synthase. These results imply that ATP synthase inhibition might mediate the antiangiogenic activity of PEDF via mechanisms similar to those used by angiostatin. Support by the NEI intramural research program