Extracellular amino acids induce the yeast SPS-sensor to endoproteolytically cleave transcription factors Stp1 and Stp2 in a process termed receptor-activated proteolysis (RAP). Ssy5, the activating endoprotease, is synthesized with a large N-terminal Pro-domain and a C-terminal chymotrypsin-like catalytic(Cat)-domain. During biogenesis, Ssy5 cleaves itself, and the Pro- and Cat-domains remain associated forming an inactive primed protease. Here we show that the Pro-domain is a potent inhibitor of Cat-domain activity and that its inactivation is a requisite for RAP. Accordingly, amino acid-induced signals trigger proteasome-dependent degradation of the Pro-domain. A mutation that stabilizes the Pro-domain prevents Stp1 processing, whereas destabilizing mutations lead to constitutive RAP-independent Stp1 processing. We fused a conditional degron to the Pro-domain to synthetically reprogram the amino acid responsive SPS signaling pathway placing it under temperature control. Our results define a regulatory mechanism that is novel for eukaryotic proteases functioning within cells.
|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|