Poly(ADP-ribosyl)ation is a post-translational modification of proteins. During this process, molecules of ADP-ribose are added successively on to acceptor proteins to form branched polymers. This modification is transient but very extensive in vivo, as polymer chains can reach more than 200 units on protein acceptors. The existence of the poly(ADP-ribose) polymer was first reported nearly 40 years ago. Since then, the importance of poly(ADP-ribose) synthesis has been established in many cellular processes. However, a clear and unified picture of the physiological role of poly(ADP-ribosyl)ation still remains to be established. The total dependence of poly(ADP-ribose) synthesis on DNA strand breaks strongly suggests that this post-translational modification is involved in the metabolism of nucleic acids. This view is also supported by the identification of direct protein-protein interactions involving poly(ADP-ribose) polymerase (113 kDa PARP), an enzyme catalysing the formation of poly(ADP-ribose), and key effectors of DNA repair, replication and transcription reactions. The presence of PARP in these multiprotein complexes, in addition to the actual poly(ADP-ribosyl)ation of some components of these complexes, clearly supports an important role for poly(ADP-ribosyl)ation reactions in DNA transactions. Accordingly, inhibition of poly(ADP-ribose) synthesis by any of several approaches and the analysis of PARP-deficient cells has revealed that the absence of poly(ADP-ribosyl)ation strongly affects DNA metabolism, most notably DNA repair. The recent identification of new poly(ADP-ribosyl)ating enzymes with distinct (non-standard) structures in eukaryotes and archaea has revealed a novel level of complexity in the regulation of poly(ADP-ribose) metabolism.

/pdf/poly-adp-ribosyl-ation-reactions-in-the-regulation-of-bcg8wwt2pc.pdf

Poly(adp-ribosyl)ation reactions in the regulation of nuclear functions

Since poly-ADP ribose was discovered over 40 years ago, there has been significant progress in research into the biology of mono- and poly-ADP-ribosylation reactions. During the last decade, it became clear that ADP-ribosylation reactions play important roles in a wide range of physiological and pathophysiological processes, including inter- and intracellular signaling, transcriptional regulation, DNA repair pathways and maintenance of genomic stability, telomere dynamics, cell differentiation and proliferation, and necrosis and apoptosis. ADP-ribosylation reactions are phylogenetically ancient and can be classified into four major groups: mono-ADP-ribosylation, poly-ADP-ribosylation, ADP-ribose cyclization, and formation of O-acetyl-ADP-ribose. In the human genome, more than 30 different genes coding for enzymes associated with distinct ADP-ribosylation activities have been identified. This review highlights the recent advances in the rapidly growing field of nuclear mono-ADP-ribosylation and poly-ADP-ribosylation reactions and the distinct ADP-ribosylating enzyme families involved in these processes, including the proposed family of novel poly-ADP-ribose polymerase-like mono-ADP-ribose transferases and the potential mono-ADP-ribosylation activities of the sirtuin family of NAD+-dependent histone deacetylases. A special focus is placed on the known roles of distinct mono- and poly-ADP-ribosylation reactions in physiological processes, such as mitosis, cellular differentiation and proliferation, telomere dynamics, and aging, as well as “programmed necrosis” (i.e., high-mobility-group protein B1 release) and apoptosis (i.e., apoptosis-inducing factor shuttling). The proposed molecular mechanisms involved in these processes, such as signaling, chromatin modification (i.e., “histone code”), and remodeling of chromatin structure (i.e., DNA damage response, transcriptional regulation, and insulator function), are described. A potential cross talk between nuclear ADP-ribosylation processes and other NAD+-dependent pathways is discussed.

https://mmbr.asm.org/content/mmbr/70/3/789.full.pdf

Nuclear ADP-Ribosylation Reactions in Mammalian Cells: Where Are We Today and Where Are We Going?

Poly-ADP-ribose metabolism plays a mayor role in a wide range of biological processes, such as maintenance of genomic stability, transcriptional regulation, energy metabolism and cell death. Poly-ADP-ribose polymerases (PARPs) are an ancient family of enzymes, as evidenced by the poly-ADP-ribosylating activities reported in dinoflagellates and archaebacteria and by the identification of Parp-like genes in eubacterial and archaeabacterial genomes. Six genes encoding "bona fide" PARP enzymes have been identified in mammalians: PARP1, PARP2, PARP3, PARP4/vPARP, PARP5/Tankyrases-1 and PARP6/Tankyrases-2. The best studied of these enzymes PARP1 plays a primary role in the process of poly-ADP-ribosylation. PARP1-mediated poly-ADP-ribosylation has been implicated in the pathogenesis of cancer, inflammatory and neurodegenerative disorders. This review will summarize the novel findings and concepts for PARP enzymes and their poly-ADP-ribosylation activity in the regulation of physiological and pathophysiological processes. A special focus is placed on the proposed molecular mechanisms involved in these processes, such as signaling, regulation of telomere dynamics, remodeling of chromatin structure and transcriptional regulation. A potential functional cross talk between PARP family members and other NAD+-consuming enzymes is discussed.

The diverse biological roles of mammalian PARPS, a small but powerful family of poly-ADP-ribose polymerases.

https://www.cell.com/cell/pdf/S0092-8674(00)81671-2.pdf

An Enzymatic Activity in the Yeast Sir2 Protein that Is Essential for Gene Silencing

ADP-ribosylation in mammalian cell ghosts. Dependence of poly(ADP-ribose) synthesis on strand breakage in DNA.

Covalently bound adducts of ply(L-lysine), bovine serum albumin, lysine rich histone (f1) and deoxyribonucleotidase I (DNase, EC 3.1.4.5) with adenosine diphosphoribose and ribose-5-phosphate were prepared at pH 7.4 and 9.5. Macromolecular adducts of bovine serum albumin and histone (f1) were isolated by gel filtration and electrophoresis. Reduction of products by NaBH4 did not dissociate the ribose-5-phosphate moiety from macromolecules. Specific introduction of 3H into the adducts also indicated Schiff base formation. The reaction of ribose-5-phosphate with epsilon-amino groups of histone (f1) approached 70-90% saturation. Spermine and spermidine also react with adenosine diphosphoribose and ribose-5-phosphate to form 1:1 Schiff bases. It is proposed that high turnover of cellular NAD+ is the source of aldehydic metabolites which may regulate macromolecular metabolism by covalent modification of nuclear proteins, whereas polyamines serve as modulators of this control cycle.

Covalent modification of proteins by metabolites of NAD

A preparation of poly(adenosine diphosphoribose) synthase obtained from pigeon liver nuclei has been used to make poly(adenosine diphosphoribose) with an average chain length of 20 Digestion of the purified poly(adenosine diphosphoribose) with snake venom phosphodiesterase (oligonucleate 5'-nucleotidohydrolase; EC 3141) gave the monomer, 2'-(5"-phosphoribosyl)-5-AMP After purification of the monomer on a Dowex-1 column, further digestion with alkaline phosphatase [orthophosphoric-monoester phosphohydrolase (alkaline optimum); EC 3131] yielded the dephosphorylated product, 2'-ribosyl adenosine Nuclear magnetic resonance spectra at 360 MHz of the 2'-ribosyl adenosine were obtained in [2H6]dimethylsulfoxide, which allows direct observation of the hydroxyl protons These spectra show the absence of the adenosine 2'-hydroxyl proton, thus confirming the 2' position as the site of attachment of the ribose to the adenosine moiety Comparison of the coupling constants and the chemical shifts of the ribose hydroxyl protons of 2'-ribosyl adenosine with the model compounds alpha- and beta-methylribofuranoside establishes an alpha (1" leads to 2') glycosidic linkage in the monomer No evidence was found for heterogeneity in either the site of attachment or configuration of the linkage in the 2'-(5"-phosphoribosyl)-5'-AMP

Ari M. Ferro

Papers

Covalent modification of proteins by metabolites of NAD

Structure of a poly (adenosine diphosphoribose) monomer: 2'-(5"-hosphoribosyl)-5'-adenosine monophosphate

Analysis of larger than tetrameric poly(adenosine diphosphoribose) by a radioimmunoassay in nuclei separated in organic solvents

Macromolecular derivatives of NAD+ in heart nuclei: poly adenosine diphosphoribose and adenosine diphosphoribose proteins.