title: Regulation of intermediary metabolism by the PKCdelta signalosome in mitochondria.
abstract: PKCδ has emerged as a novel regulatory molecule of oxidative phosphorylation by targeting the pyruvate dehydrogenase complex (PDHC). We showed that activation of PKCδ leads to the dephosphorylation of pyruvate dehydrogenase kinase 2 (PDK2), thereby decreasing PDK2 activity and increasing PDH activity, accelerating oxygen consumption, and augmenting ATP synthesis. However, the molecular components that mediate PKCδ signaling in mitochondria have remained elusive so far. Here, we identify for the first time a functional complex, which includes cytochrome c as the upstream driver of PKCδ, and uses the adapter protein p66Shc as a platform with vitamin A (retinol) as a fourth partner. All four components are necessary for the activation of the PKCδ signal chain. Genetic ablation of any one of the three proteins, or retinol depletion, silences signaling. Furthermore, mutations that disrupt the interaction of cytochrome c with p66Shc, of p66Shc with PKCδ, or the deletion of the retinol-binding pocket on PKCδ, attenuate signaling. In cytochrome c-deficient cells, reintroduction of cytochrome c Fe(3+) protein restores PKCδ signaling. Taken together, these results indicate that oxidation of PKCδ is key to the activation of the pathway. The PKCδ/p66Shc/cytochrome c signalosome might have evolved to effect site-directed oxidation of zinc-finger structures of PKCδ, which harbor the activation centers and the vitamin A binding sites. Our findings define the molecular mechanisms underlying the signaling function of PKCδ in mitochondria.
authors.affiliation: Department of Neurology and Neurobiology, Weill-Cornell Medical School, New York, New York, USA.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Acin-Perez
authors.forename: Beatrice
authors.initials: B
authors.lastname: Hoyos
authors.forename: Jianli
authors.initials: J
authors.lastname: Gong
authors.forename: Valerie
authors.initials: V
authors.lastname: Vinogradov
authors.forename: Donald A
authors.initials: DA
authors.lastname: Fischman
authors.forename: Michael
authors.initials: M
authors.lastname: Leitges
authors.forename: Babak
authors.initials: B
authors.lastname: Borhan
authors.forename: Anatoly
authors.initials: A
authors.lastname: Starkov
authors.forename: Giovanni
authors.initials: G
authors.lastname: Manfredi
authors.forename: Ulrich
authors.initials: U
authors.lastname: Hammerling
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D045304:Cytochromes c / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008928:Mitochondria / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D051745:Protein Kinase C-delta / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011767:Pyruvate Decarboxylase / Q000235:genetics / Q000378:metabolism; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D055765:Shc Signaling Adaptor Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D014801:Vitamin A / Q000235:genetics / Q000378:metabolism
chemical_list: D046912:Multiprotein Complexes; C000631435:Pdk2 protein, mouse; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D055765:Shc Signaling Adaptor Proteins; C528034:Shc1 protein, mouse; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D014801:Vitamin A; D045304:Cytochromes c; D017346:Protein Serine-Threonine Kinases; D051745:Protein Kinase C-delta; D011767:Pyruvate Decarboxylase
references.citation: FASEB J. 2005 Aug;19(10):1323-5
references.pmid: 15946993
references.citation: FASEB J. 2008 Nov;22(11):3878-87
references.pmid: 18676402
references.citation: Cell Growth Differ. 2001 Sep;12(9):465-70
references.pmid: 11571229
references.citation: Curr Opin Struct Biol. 1997 Aug;7(4):557-65
references.pmid: 9266179
references.citation: Am J Physiol Renal Physiol. 2010 May;298(5):F1214-21
references.pmid: 20053790
references.citation: Proc Natl Acad Sci U S A. 1997 Oct 14;94(21):11233-7
references.pmid: 9326592
references.citation: FASEB J. 2010 Feb;24(2):627-36
references.pmid: 19812372
references.citation: J Biol Chem. 2004 Jan 30;279(5):3596-604
references.pmid: 14600145
references.citation: Science. 1992 Oct 23;258(5082):607-14
references.pmid: 1411571
references.citation: J Biol Chem. 2000 Aug 4;275(31):24136-45
references.pmid: 10823825
references.citation: Circ Res. 2005 Jul 8;97(1):78-85
references.pmid: 15961716
references.citation: J Biol Chem. 2005 Feb 25;280(8):6872-8
references.pmid: 15591313
references.citation: Stroke. 2005 Dec;36(12):2781-90
references.pmid: 16254221
references.citation: FASEB J. 1995 Apr;9(7):484-96
references.pmid: 7737456
references.citation: J Biochem. 2008 Jan;143(1):31-8
references.pmid: 17956904
references.citation: J Biol Chem. 2002 Jun 28;277(26):23949-57
references.pmid: 11971897
references.citation: J Clin Invest. 2003 Mar;111(6):769-78
references.pmid: 12639979
references.citation: J Biol Chem. 2008 May 23;283(21):14430-44
references.pmid: 18375950
references.citation: Circulation. 2003 Nov 11;108(19):2304-7
references.pmid: 14597593
references.citation: Cell. 1999 Feb 5;96(3):341-52
references.pmid: 10025400
references.citation: J Biol Chem. 2001 Dec 14;276(50):46925-32
references.pmid: 11595737
references.citation: Cell Metab. 2009 Mar;9(3):265-76
references.pmid: 19254571
references.citation: Am J Physiol Heart Circ Physiol. 2004 Aug;287(2):H946-56
references.pmid: 15277209
references.citation: Methods. 2002 Apr;26(4):292-7
references.pmid: 12054919
references.citation: FASEB J. 2001 Jan;15(1):28-30
references.pmid: 11099483
references.citation: Biochem Soc Trans. 2006 Apr;34(Pt 2):217-22
references.pmid: 16545080
references.citation: Biochemistry. 2002 Dec 24;41(51):15360-8
references.pmid: 12484775
references.citation: Structure. 2001 May 9;9(5):377-87
references.pmid: 11377198
references.citation: Cell. 2005 Jul 29;122(2):221-33
references.pmid: 16051147
references.citation: Pharmacol Res. 2007 Jun;55(6):523-36
references.pmid: 17576073
references.citation: Cell. 1995 Jun 16;81(6):917-24
references.pmid: 7781068
references.citation: J Biol Chem. 2002 Nov 15;277(46):44327-31
references.pmid: 12213816
references.citation: J Biochem. 2002 Dec;132(6):831-9
references.pmid: 12473183
references.citation: Methods Cell Biol. 2007;80:155-71
references.pmid: 17445693
references.citation: J Biol Chem. 1996 May 31;271(22):13155-61
references.pmid: 8662757