Nitric oxide (NO) induces nitration of protein kinase Cepsilon (PKCepsilon ), facilitating PKCepsilon translocation via enhanced PKCepsilon -RACK2 interactions: a novel mechanism of no-triggered activation of PKCepsilon.
Activation of protein kinase C (PKC) epsilon by nitric oxide (NO) has been implicated in the development of cardioprotection. However, the cellular mechanisms underlying the activation of PKCepsilon by NO remain largely unknown. Nitration of protein tyrosine residues has been shown to alter functions of a variety of proteins, and NO-derived peroxynitrite is known as a strong nitrating agent. In this investigation, we demonstrate that NO donors promote translocation and activation of PKCepsilon in an NO- and peroxynitrite-dependent fashion. NO induces peroxynitrite-mediated tyrosine nitration of PKCepsilon in rabbit cardiomyocytes in vitro, and nitrotyrosine residues were also detected on PKCepsilon in vivo in the rabbit myocardium preconditioned with NO donors. Furthermore, coimmunoprecipitation of PKCepsilon and its receptor for activated C kinase, RACK2, illustrated a peroxynitrite-dependent increase in PKCepsilon-RACK2 interactions in NO donor-treated cardiomyocytes. Moreover, using an enzyme-linked immunosorbent assay-based protein-protein interaction assay, PKCepsilon proteins treated with the peroxynitrite donor SIN-1 exhibited enhanced binding to RACK2 in an acellular environment. Our data demonstrate that post-translational modification of PKCepsilon by NO donors, namely nitration of PKCepsilon, facilitates its interaction with RACK2 and promotes translocation and activation of PKCepsilon. These findings offer a plausible novel mechanism by which NO activates the PKC signaling pathway.
Balafanova
Zarema
Z
Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky 40202, USA.
Bolli
Roberto
R
Zhang
Jun
J
Zheng
Yuting
Y
Pass
Jason M
JM
Bhatnagar
Aruni
A
Tang
Xian-Liang
XL
Wang
Ouli
O
Cardwell
Ernest
E
Ping
Peipei
P
D000595:Amino Acid Sequence; D000818:Animals; D004789:Enzyme Activation; D007527:Isoenzymes / Q000378:metabolism*; D008969:Molecular Sequence Data; D009566:Nitrates / Q000378:metabolism*; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D051744:Protein Kinase C-epsilon; D021381:Protein Transport; D011817:Rabbits; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology
D007527:Isoenzymes; D009566:Nitrates; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D026423:S-Nitroso-N-Acetylpenicillamine; D011493:Protein Kinase C; D051744:Protein Kinase C-epsilon