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Pigment epithelium‐derived factor binds to cell‐surface F 1 ‐ATP synthase
Author(s) -
Notari Luigi,
Arakaki Naokatu,
Mueller David,
Meier Scott,
Amaral Juan,
Becerra S. P.
Publication year - 2010
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2010.07641.x
Subject(s) - pedf , endothelial stem cell , biochemistry , chemistry , angiogenesis , protein subunit , biology , angiostatin , microbiology and biotechnology , biophysics , in vitro , retinal , cancer research , gene
Pigment epithelium‐derived factor (PEDF), a potent blocker of angiogenesis in vivo , and of endothelial cell migration and tubule formation, binds with high affinity to an as yet unknown protein on the surfaces of endothelial cells. Given that protein fingerprinting suggested a match of a ∼ 60 kDa PEDF‐binding protein in bovine retina with Bos taurus F 1 ‐ATP synthase β‐subunit, and that F 1 F o ‐ATP synthase components have been identified recently as cell‐surface receptors, we examined the direct binding of PEDF to F 1 . Size‐exclusion ultrafiltration assays showed that recombinant human PEDF formed a complex with recombinant yeast F 1 . Real‐time binding as determined by surface plasmon resonance demonstrated that yeast F 1 interacted specifically and reversibly with human PEDF. Kinetic evaluations revealed high binding affinity for PEDF, in agreement with PEDF affinities for endothelial cell surfaces. PEDF blocked interactions between F 1 and angiostatin, another antiangiogenic factor, suggesting overlapping PEDF‐binding and angiostatin‐binding sites on F 1 . Surfaces of endothelial cells exhibited affinity for PEDF‐binding proteins of ∼ 60 kDa. Antibodies to F 1 β‐subunit specifically captured PEDF‐binding components in endothelial plasma membranes. The extracellular ATP synthesis activity of endothelial cells was examined in the presence of PEDF. PEDF significantly reduced the amount of extracellular ATP produced by endothelial cells, in agreement with direct interactions between cell‐surface ATP synthase and PEDF. In addition to demonstrating that PEDF binds to cell‐surface F 1 , these results show that PEDF is a ligand for endothelial cell‐surface F 1 F o ‐ATP synthase. They suggest that PEDF‐mediated inhibition of ATP synthase may form part of the biochemical mechanisms by which PEDF exerts its antiangiogenic activity. Structured digital abstract• MINT‐7711286 : angiostatin (uniprotkb: P00747 ) physically interacts ( MI:0915 ) with F‐ATPase alpha subunit (uniprotkb: P07251 ), F‐ATPase beta subunit (uniprotkb: P00830 ), F‐ATPase gamma subunit (uniprotkb: P38077 ), F‐ATPase delta subunit (uniprotkb: Q12165 ) and F‐ATPase epsilon subunit (uniprotkb: P21306 ) by competition binding ( MI:0405 ) • MINT‐7711113 : angiostatin (uniprotkb: P00747 ) physically interacts ( MI:0915 ) with F‐ATPase epsilon subunit (uniprotkb: P21306 ), F‐ATPase delta subunit (uniprotkb: Q12165 ), F‐ATPase gamma subunit (uniprotkb: P38077 ), F‐ATPase beta subunit (uniprotkb: P00830 ) and F‐ATPase alpha subunit (uniprotkb: P07251 ) by surface plasmon resonance ( MI:0107 ) • MINT‐7711060 : F‐ATPase gamma subunit (uniprotkb: P38077 ), F‐ATPase beta subunit (uniprotkb: P00830 ), F‐ATPase alpha subunit (uniprotkb: P07251 ) and PEDF (uniprotkb: P36955 ) physically interact ( MI:0915 ) by molecular sieving ( MI:0071 ) • MINT‐7711313 : F‐ATPase epsilon subunit (uniprotkb: P21306 ), F‐ATPase delta subunit (uniprotkb: Q12165 ), PEDF (uniprotkb: P36955 ), F‐ATPase alpha subunit (uniprotkb: P07251 ), F‐ATPase beta subunit (uniprotkb: P00830 ) and F‐ATPase gamma subunit (uniprotkb: P38077 ) physically interact ( MI:0915 ) by molecular sieving ( MI:0071 ) • MINT‐7711083 : PEDF (uniprotkb: P36955 ) physically interacts ( MI:0915 ) with F‐ATPase epsilon subunit (uniprotkb: P21306 ), F‐ATPase delta subunit (uniprotkb: Q12165 ), F‐ATPase gamma subunit (uniprotkb: P38077 ), F‐ATPase beta subunit (uniprotkb: P00830 ) and F‐ATPase alpha subunit (uniprotkb: P07251 ) by surface plasmon resonance ( MI:0107 )