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Molecular comparison of WT and F92A Caveolin‐1: Direction towards increasing Nitric Oxide bioavailability
Author(s) -
Sharma Arpeeta,
Yu Carol,
Bernatchez Pascal
Publication year - 2010
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.24.1_supplement.235.9
Subject(s) - enos , caveolae , caveolin 1 , nitric oxide , chemistry , caveolin , mutant , bioavailability , wild type , nitric oxide synthase type iii , biochemistry , microbiology and biotechnology , nitric oxide synthase , enzyme , cell , biology , pharmacology , gene , organic chemistry
Endothelial dysfunction is characterized by the loss of endothelial cell (EC)‐derived Nitric Oxide (NO) release and increased superoxide anion (O 2 − ). Endothelial NO synthase (eNOS) is the enzyme that synthesizes NO and O 2 − in physiological and pathological settings, respectively. Caveolin‐1 (Cav‐1) is the major coat protein of caveolae that binds to and inhibits eNOS NO release, and we have shown that Cav‐1 F92 is the amino acid that inhibits NO release (Bernatchez, PNAS 2005). Interestingly, our unpublished observations show that F92A Cav‐1 mutant can INCREASE NO release. OBJECTIVE To determine how F92A Cav‐1 increases NO release METHODS We performed a biochemical comparison of WT vs F92A Cav‐1 to determine if the F92A mutation affects its activity. We also looked at Cav‐1 F92A substitution on eNOS O 2 − release. RESULTS WT Cav‐1 (25kDa) targets to caveolae and oligomerizes into high MW homo‐oligomers (350–600 kDa). Interestingly, F92A Cav‐1 enrichment in caveolae and homo‐oligomers are identical to WT Cav‐1, and by GST pulldown assays we show that WT and F92A Cav‐1 bind identically to eNOS. However, we have observed that F92A Cav‐1 can decrease O 2 − release as compared to WT Cav‐1. CONCLUSION These data show that F92A Cav‐1 binds eNOS, prevents WT Cav‐1 inhibition of eNOS and decreases O 2 − release, and suggest that eNOS‐Cav‐1 interaction is a therapeutic target for improving NO bioavailability.