title: Poly(ADP-ribosyl)ation is required to modulate chromatin changes at c-MYC promoter during emergence from quiescence.
abstract: Poly(ADP-ribosyl)ation is a post-translational modification of various proteins and participates in the regulation of chromatin structure and transcription through complex mechanisms not completely understood. We have previously shown that PARP-1, the major family member of poly(ADP-ribose)polymerases, plays an important role in the cell cycle reactivation of resting cells by regulating the expression of Immediate Early Response Genes, such as c-MYC, c-FOS, JUNB and EGR-1. In the present work we have investigated the molecular mechanisms by which the enzyme induces c-MYC transcription upon serum stimulation of quiescent cells. We show that PARP-1 is constitutively associated in vivo to a c-MYC promoter region recognized as biologically relevant for the transcriptional regulation of the gene. Moreover, we report that serum stimulation causes the prompt accumulation of ADP-ribose polymers on the same region and that this modification is required for chromatin decondensation and for the exchange of negative for positive transcriptional regulators. Finally we provide evidence that the inhibition of PARP activity along with serum stimulation impairs c-MYC induction by preventing the proper accumulation of histone H3 phosphoacetylation, a specific chromatin mark for the activation of Immediate Early Response Genes. These findings not only suggest a novel strategy by which PARP-1 regulates the transcriptional activity of promoters but also provide new information about the complex regulation of c-MYC expression, a critical determinant of the transition from quiescence to proliferation.
authors.affiliation: Department of Cellular Biotechnologies and Hematology, Sapienza University, Rome, Italy; Pasteur Institute-Fondazione Cenci Bolognetti, Rome, Italy.
authors.forename: Cassandra
authors.initials: C
authors.lastname: Mostocotto
authors.affiliation: Department of Cellular Biotechnologies and Hematology, Sapienza University, Rome, Italy; Pasteur Institute-Fondazione Cenci Bolognetti, Rome, Italy.
authors.forename: Mariarosaria
authors.initials: M
authors.lastname: Carbone
authors.affiliation: Department of Cellular Biotechnologies and Hematology, Sapienza University, Rome, Italy; Pasteur Institute-Fondazione Cenci Bolognetti, Rome, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Battistelli
authors.affiliation: Department of Cellular Biotechnologies and Hematology, Sapienza University, Rome, Italy; Pasteur Institute-Fondazione Cenci Bolognetti, Rome, Italy.
authors.forename: Agnese
authors.initials: A
authors.lastname: Ciotti
authors.affiliation: Department of Cellular Biotechnologies and Hematology, Sapienza University, Rome, Italy; Pasteur Institute-Fondazione Cenci Bolognetti, Rome, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Amati
authors.affiliation: Department of Cellular Biotechnologies and Hematology, Sapienza University, Rome, Italy; Pasteur Institute-Fondazione Cenci Bolognetti, Rome, Italy.
authors.forename: Rossella
authors.initials: R
authors.lastname: Maione
mesh_terms: D002460:Cell Line; D002843:Chromatin / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D000071137:Poly (ADP-Ribose) Polymerase-1; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics*; D015533:Transcriptional Activation
chemical_list: D002843:Chromatin; D006657:Histones; D016271:Proto-Oncogene Proteins c-myc; D011064:Poly Adenosine Diphosphate Ribose; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases