Specificity and recognition of the ADPr-Ub modification in the DNA damage response

ABSTRACT: ADP-ribosylation (ADPr) is a post-translational modification that has regulatory roles in multiple cellular pathways including the DNA damage response and in innate immunity. Recently it has been uncovered that ADP-ribose can be further modified by a family of ubiquitin E3 ligases, the DELTEXES, which will catalyse ubiquitin transfer directly onto ADP-ribose, creating a hybrid ADPr-Ub modification which can be recognised by proteins with dedicated ADPr-Ub binding domains. With this hybrid modification recently been identified in cellular system, we use a series of in vitro and cellular assays to investigate the amino acid preference for ADPr-Ub production as well as investigating conditions required for reversal of the modification. We show that ADPr on both serine and glutamate-linked peptides can be ubiquitinated by the RING-DTC domains of DTX2 and DTX3L in vitro and that this can be recognised by RNF114, RNF138 and RNF166 for ubiquitin chain elongation. Finally, we demonstrate that DTX2 rather than DTX3L plays a role in ADPr-Ub production at sites of damage to promote the recruitment of RNF114, RNF138 and RNF166 in HPF1-independent manner.

SUBMITTER: Rebecca Smith 

PROVIDER: S-BIAD2514 | bioimages |

REPOSITORIES: bioimages