The Slx5-Slx8 complex is a ubiquitin ligase that preferentially ubiquitylates SUMOylated substrates, targeting them for proteolysis. Mutations in SLX5, SLX8, and other SUMO pathway genes were previously identified in our lab as genomic suppressors of a point mutation (mot1-301) in the transcriptional regulator MOT1. To further understand the links between the SUMO and ubiquitin pathways, a screen was performed for high copy suppressors of mot1-301, yielding three genes (MOT3, MIT1 and ULS1). MOT3 and MIT1 have characteristics of prions, and ULS1 is believed to encode another SUMO-targeted ubiquitin ligase (STUbL) that functionally overlaps with Slx5-Slx8. Here we focus on ULS1, obtaining results suggesting that the relationship between ULS1 and SLX5 is more complex than expected. Uls1 interacted with Slx5 physically by yeast two-hybrid and co-immunoprecipitation assays, a uls1 mutation that blocked the interaction between ULS1 and SLX5 interfered with ULS1 function, and genetic analyses indicated an antagonistic relationship between ULS1 and SLX5. Combined, our results challenge the assumption that Uls1 and Slx5 are simply partially overlapping STUbLs and begin to illuminate a regulatory relationship between these two proteins.
|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||Annotation Extension||Reference|
|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||Assay||Construct||Conditions||Strain Background||Reference|