title: PARP1 represses PAP and inhibits polyadenylation during heat shock.
abstract: The 3' ends of most eukaryotic mRNAs are produced by an endonucleolytic cleavage followed by synthesis of a poly(A) tail. Poly(A) polymerase (PAP), the enzyme that catalyzes the formation of the tail, is subject to tight regulation involving several posttranslational modifications. Here we show that the enzyme poly(ADP-ribose) polymerase 1 (PARP1) modifies PAP and regulates its activity both in vitro and in vivo. PARP1 binds to and modifies PAP by poly(ADP-ribosyl)ation (PARylation) in vitro, which inhibits PAP activity. In vivo we show that PAP is PARylated during heat shock, leading to inhibition of polyadenylation in a PARP1-dependent manner. The observed inhibition reflects reduced RNA binding affinity of PARylated PAP in vitro and decreased PAP association with non-heat shock protein-encoding genes in vivo. Our results provide direct evidence that PARylation can control processing of mRNA precursors, and also identify PARP1 as a regulator of polyadenylation during thermal stress.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
authors.forename: Dafne Campigli
authors.initials: DC
authors.lastname: Di Giammartino
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Shi
authors.forename: James L
authors.initials: JL
authors.lastname: Manley
mesh_terms: D002460:Cell Line; D004789:Enzyme Activation; D055785:Gene Knockdown Techniques; D018869:Heat-Shock Response; D006801:Humans; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D026723:Polyadenylation; D011062:Polynucleotide Adenylyltransferase / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D055544:beta-Globins / Q000235:genetics / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D055544:beta-Globins; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D011062:Polynucleotide Adenylyltransferase