Gagné JP, Moreel X, Gagné P, Labelle Y, Droit A, Chevalier-Paré M, Bourassa S, McDonald D, Hendzel MJ, Prigent C, Poirier GG. Proteomic investigation of phosphorylation sites in poly(ADP-ribose) polymerase-1 and poly(ADP-ribose) glycohydrolase.
J Proteome Res 2009;
8:1014-29. [PMID:
19105632 DOI:
10.1021/pr800810n]
[Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Phosphorylation is a very common post-translational modification event known to modulate a wide range of biological responses. Beyond the regulation of protein activity, the interrelation of phosphorylation with other post-translational mechanisms is responsible for the control of diverse signaling pathways. Several observations suggest that phosphorylation of poly(ADP-ribose) polymerase-1 (PARP-1) regulates its activity. There is also accumulating evidence to suggest the establishment of phosphorylation-dependent assembly of PARP-1-associated multiprotein complexes. Although it is relatively straightforward to demonstrate phosphorylation of a defined target, identification of the actual amino acids involved still represents a technical challenge for many laboratories. With the use of a combination of bioinformatics-based predictions tools for generic and kinase-specific phosphorylation sites, in vitro phosphorylation assays and mass spectrometry analysis, we investigated the phosphorylation profile of PARP-1 and poly(ADP-ribose) glycohydrolase (PARG), two major enzymes responsible for poly(ADP-ribose) turnover. Mass spectrometry analysis revealed the phosphorylation of several serine/threonine residues within important regulatory domains and motifs of both enzymes. With the use of in vivo microirradiation-induced DNA damage, we show that altered phosphorylation at specific sites can modify the dynamics of assembly and disassembly of PARP-1 at sites of DNA damage. By documenting and annotating a collection of known and newly identified phosphorylation sites, this targeted proteomics study significantly advances our understanding of the roles of phosphorylation in the regulation of PARP-1 and PARG.
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