Two ubiquitin-conjugating enzymes, RAD6 and the heteromeric UBC13-MMS2 complex, have been implicated in post-replicative DNA damage repair in yeast. Here we provide a mechanistic basis for cooperation between the two enzymes. We show that two chromatin-associated RING finger proteins, RAD18 and RAD5, play a central role in mediating physical contacts between the members of the RAD6 pathway. RAD5 recruits the UBC13-MMS2 complex to DNA by means of its RING finger domain. Moreover, RAD5 association with RAD18 brings UBC13-MMS2 into contact with the RAD6-RAD18 complex. Interaction between the two RING finger proteins thus promotes the formation of a heteromeric complex in which the two distinct ubiquitin-conjugating activities of RAD6 and UBC13-MMS2 can be closely coordinated. Surprisingly, UBC13 and MMS2 are largely cytosolic proteins, but DNA damage triggers their redistribution to the nucleus. These findings suggest a mechanism by which the activity of this DNA repair pathway could be regulated.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|