Nitroxyl activates SERCA in cardiac myocytes via glutathiolation of cysteine 674.
Nitroxyl (HNO) exerts inotropic and lusitropic effects in myocardium, in part via activation of SERCA (sarcoplasmic reticulum calcium ATPase). To elucidate the molecular mechanism, adult rat ventricular myocytes were exposed to HNO derived from Angeli's salt. HNO increased the maximal rate of thapsigargin-sensitive Ca2+ uptake mediated by SERCA in sarcoplasmic vesicles and caused reversible oxidative modification of SERCA thiols. HNO increased the S-glutathiolation of SERCA, and adenoviral overexpression of glutaredoxin-1 prevented both the HNO-stimulated oxidative modification of SERCA and its activation, as did overexpression of a mutated SERCA in which cysteine 674 was replaced with serine. Thus, HNO increases the maximal activation of SERCA via S-glutathiolation at cysteine 674.
Lancel
Steve
S
Cardiovascular Medicine Section, Boston University Medical Center, 88 E Newton St, Boston, MA 02118, USA.
Zhang
Jingmei
J
Evangelista
Alicia
A
Trucillo
Mario P
MP
Tong
Xiaoyong
X
Siwik
Deborah A
DA
Cohen
Richard A
RA
Colucci
Wilson S
WS
D000256:Adenoviridae; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002460:Cell Line; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D054477:Glutaredoxins / Q000096:biosynthesis / Q000235:genetics; D005978:Glutathione / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009154:Mutation; D009206:Myocardium / Q000201:enzymology*; D032383:Myocytes, Cardiac / Q000201:enzymology*; D009573:Nitrites / Q000737:chemistry / Q000494:pharmacology; D009589:Nitrogen Oxides / Q000737:chemistry / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects* / Q000235:genetics; D051381:Rats; D012519:Sarcoplasmic Reticulum / Q000201:enzymology / Q000235:genetics; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism*; D014161:Transduction, Genetic
D000975:Antioxidants; C516007:Glrx protein, rat; D054477:Glutaredoxins; D009573:Nitrites; D009589:Nitrogen Oxides; C021229:oxyhyponitrite; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D005978:Glutathione; C039900:nitroxyl; D003545:Cysteine