title: 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.
abstract: 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.
authors.affiliation: Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky 40202, USA.
authors.forename: Zarema
authors.initials: Z
authors.lastname: Balafanova
authors.forename: Roberto
authors.initials: R
authors.lastname: Bolli
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Yuting
authors.initials: Y
authors.lastname: Zheng
authors.forename: Jason M
authors.initials: JM
authors.lastname: Pass
authors.forename: Aruni
authors.initials: A
authors.lastname: Bhatnagar
authors.forename: Xian-Liang
authors.initials: XL
authors.lastname: Tang
authors.forename: Ouli
authors.initials: O
authors.lastname: Wang
authors.forename: Ernest
authors.initials: E
authors.lastname: Cardwell
authors.forename: Peipei
authors.initials: P
authors.lastname: Ping
mesh_terms: 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
chemical_list: 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