TY - JOUR
T1 - Cardiac nitric oxide synthase-1 localization within the cardiomyocyte is accompanied by the adaptor protein, CAPON
AU - Beigi, Farideh
AU - Oskouei, Behzad N.
AU - Zheng, Meizi
AU - Cooke, Carol A.
AU - Lamirault, Guillaume
AU - Hare, Joshua M.
PY - 2009/12/15
Y1 - 2009/12/15
N2 - The mechanism(s) regulating nitric oxide synthase-1 (NOS1) localization within the cardiac myocyte in health and disease remains unknown. Here we tested the hypothesis that the PDZ-binding domain interaction between CAPON (carboxy-terminal PDZ ligand of NOS1), a NOS1 adaptor protein and NOS1, contribute to NOS1 localization in specific organelles within cardiomyocytes. Ventricular cardiomyocytes and whole heart homogenates were isolated from sham and post-myocardial infarction (MI) wild-type (C57BL/6) and NOS1-/- female mice for quantification of CAPON protein expression levels. NOS1, CAPON, xanthine oxidoreductase and Dexras1, a CAPON binding partner, were all present and enriched in isolated cardiac sarcoplasmic reticulum (SR) fractions. CAPON co-immunoprecipitated with the mu and alpha isoforms of NOS1 in whole heart lysates, and co-localization of CAPON and NOS1 was demonstrated in the SR and mitochondria with dual immuno-gold electron microscopy. Following MI, CAPON and NOS1 both redistributed to caveolae and colocalized with caveolin-3. In addition, following MI, expression level of CAPON remained unchanged and Dexras1 was reduced, CAPON binding to xanthine oxidoreductase was augmented and the plasma membrane calcium ATPase (PMCA) increased. In NOS1 deficient myocytes, CAPON abundance in the SR was reduced, and redistribution to caveolae and PMCA binding after MI was absent. Together these findings support the hypothesis that NOS1 redistribution in injured myocardium requires the formation of a complex with the PDZ adaptor protein CAPON.
AB - The mechanism(s) regulating nitric oxide synthase-1 (NOS1) localization within the cardiac myocyte in health and disease remains unknown. Here we tested the hypothesis that the PDZ-binding domain interaction between CAPON (carboxy-terminal PDZ ligand of NOS1), a NOS1 adaptor protein and NOS1, contribute to NOS1 localization in specific organelles within cardiomyocytes. Ventricular cardiomyocytes and whole heart homogenates were isolated from sham and post-myocardial infarction (MI) wild-type (C57BL/6) and NOS1-/- female mice for quantification of CAPON protein expression levels. NOS1, CAPON, xanthine oxidoreductase and Dexras1, a CAPON binding partner, were all present and enriched in isolated cardiac sarcoplasmic reticulum (SR) fractions. CAPON co-immunoprecipitated with the mu and alpha isoforms of NOS1 in whole heart lysates, and co-localization of CAPON and NOS1 was demonstrated in the SR and mitochondria with dual immuno-gold electron microscopy. Following MI, CAPON and NOS1 both redistributed to caveolae and colocalized with caveolin-3. In addition, following MI, expression level of CAPON remained unchanged and Dexras1 was reduced, CAPON binding to xanthine oxidoreductase was augmented and the plasma membrane calcium ATPase (PMCA) increased. In NOS1 deficient myocytes, CAPON abundance in the SR was reduced, and redistribution to caveolae and PMCA binding after MI was absent. Together these findings support the hypothesis that NOS1 redistribution in injured myocardium requires the formation of a complex with the PDZ adaptor protein CAPON.
KW - CAPON
KW - Dexras1
KW - Heart failure
KW - Nitric oxide synthase-1 (NOS1)
KW - PDZ-interaction
KW - PMCA
UR - http://www.scopus.com/inward/record.url?scp=71849110674&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=71849110674&partnerID=8YFLogxK
U2 - 10.1016/j.niox.2009.09.005
DO - 10.1016/j.niox.2009.09.005
M3 - Article
C2 - 19800018
AN - SCOPUS:71849110674
SN - 1089-8603
VL - 21
SP - 226
EP - 233
JO - Nitric Oxide - Biology and Chemistry
JF - Nitric Oxide - Biology and Chemistry
IS - 3-4
ER -