title: DNA-independent PARP-1 activation by phosphorylated ERK2 increases Elk1 activity: a link to histone acetylation.
abstract: PolyADP-ribose polymerases (PARPs) catalyze a posttranslational modification of nuclear proteins by polyADP-ribosylation. The catalytic activity of the abundant nuclear protein PARP-1 is stimulated by DNA strand breaks, and PARP-1 activation is required for initiation of DNA repair. Here we show that PARP-1 also acts within extracellular signal-regulated kinase (ERK) signaling cascade that mediates growth and differentiation. The findings reveal an alternative mode of PARP-1 activation, which does not involve binding to DNA or DNA damage. In a cell-free system, recombinant PARP-1 was intensively activated and thereby polyADP-ribosylated by a direct interaction with phosphorylated ERK2, and the activated PARP-1 dramatically increased ERK2-catalyzed phosphorylation of the transcription factor Elk1. In cortical neurons treated with nerve growth factors and in stimulated cardiomyocytes, PARP-1 activation enhanced ERK-induced Elk1-phosphorylation, core histone acetylation, and transcription of the Elk1-target gene c-fos. These findings constitute evidence for PARP-1 activity within the ERK signal-transduction pathway.
authors.affiliation: Neufeld Cardiac Research Institute, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv 69978, Israel. marmon@post.tau.ac.il
authors.forename: Malka
authors.initials: M
authors.lastname: Cohen-Armon
authors.forename: Leonid
authors.initials: L
authors.lastname: Visochek
authors.forename: Dana
authors.initials: D
authors.lastname: Rozensal
authors.forename: Adi
authors.initials: A
authors.lastname: Kalal
authors.forename: Ilona
authors.initials: I
authors.lastname: Geistrikh
authors.forename: Rodika
authors.initials: R
authors.lastname: Klein
authors.forename: Sarit
authors.initials: S
authors.lastname: Bendetz-Nezer
authors.forename: Zhong
authors.initials: Z
authors.lastname: Yao
authors.forename: Rony
authors.initials: R
authors.lastname: Seger
mesh_terms: D000107:Acetylation; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002474:Cell-Free System; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004789:Enzyme Activation; D015870:Gene Expression; D016762:Genes, fos; D006657:Histones / Q000378:metabolism*; D066298:In Vitro Techniques; D020935:MAP Kinase Signaling System; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D010766:Phosphorylation; D000071137:Poly (ADP-Ribose) Polymerase-1; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D050807:ets-Domain Protein Elk-1 / Q000235:genetics / Q000378:metabolism*
chemical_list: C494114:Elk1 protein, rat; D006657:Histones; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D050807:ets-Domain Protein Elk-1; D004247:DNA; C499322:Parp1 protein, rat; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D019950:Mitogen-Activated Protein Kinase 1