Investigation of PARP-1, PARP-2, and PARG interactomes by affinity-purification mass spectrometry
1 Axe cancer, CHUQ Research Center, Faculty of Medicine, Laval University, 2705 Boulevard Laurier, Québec, Canada, G1V 4G2
2 CNRS UMR 6061 Institut de Génétique et Développement de Rennes, Université de Rennes 1, IFR140, 2 Avenue du Pr Léon Bernard, Rennes, France
3 Department of Oncology, University of Alberta and Cross Cancer Institute, Edmonton, Alberta, Canada, T6G 1Z2
4 Proteomics Platform of the Quebec Genomics Center, Centre de recherche du CHUQ - CRCHUL, 2705 Boulevard Laurier, Québec, Canada, G1V 4G2
Proteome Science 2010, 8:22 doi:10.1186/1477-5956-8-22Published: 13 April 2010
Poly(ADP-ribose) polymerases (PARPs) catalyze the formation of poly(ADP-ribose) (pADPr), a post-translational modification involved in several important biological processes, namely surveillance of genome integrity, cell cycle progression, initiation of the DNA damage response, apoptosis, and regulation of transcription. Poly(ADP-ribose) glycohydrolase (PARG), on the other hand, catabolizes pADPr and thereby accounts for the transient nature of poly(ADP-ribosyl)ation. Our investigation of the interactomes of PARP-1, PARP-2, and PARG by affinity-purification mass spectrometry (AP-MS) aimed, on the one hand, to confirm current knowledge on these interactomes and, on the other hand, to discover new protein partners which could offer insights into PARPs and PARG functions.
PARP-1, PARP-2, and PARG were immunoprecipitated from human cells, and pulled-down proteins were separated by gel electrophoresis prior to in-gel trypsin digestion. Peptides were identified by tandem mass spectrometry. Our AP-MS experiments resulted in the identifications of 179 interactions, 139 of which are novel interactions. Gene Ontology analysis of the identified protein interactors points to five biological processes in which PARP-1, PARP-2 and PARG may be involved: RNA metabolism for PARP-1, PARP-2 and PARG; DNA repair and apoptosis for PARP-1 and PARP-2; and glycolysis and cell cycle for PARP-1.
This study reveals several novel protein partners for PARP-1, PARP-2 and PARG. It provides a global view of the interactomes of these proteins as well as a roadmap to establish the systems biology of poly(ADP-ribose) metabolism.