Premium
Feedback‐regulated degradation of the transcriptional activator Met4 is triggered by the SCF Met30 complex
Author(s) -
Rouillon Astrid,
Barbey Régine,
Patton E.Elizabeth,
Tyers Mike,
Thomas Dominique
Publication year - 2000
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/19.2.282
Subject(s) - research centre , library science , humanities , art , art history , computer science
Saccharomyces cerevisiae SCF Met30 ubiquitin–protein ligase controls cell cycle function and sulfur amino acid metabolism. We report here that the SCF Met30 complex mediates the transcriptional repression of the MET gene network by triggering degradation of the transcriptional activator Met4p when intracellular S ‐adenosylmethionine (AdoMet) increases. This AdoMet‐induced Met4p degradation is dependent upon the 26S proteasome function. Unlike Met4p, the other components of the specific transcriptional activation complexes that are assembled upstream of the MET genes do not appear to be regulated at the protein level. We provide evidence that the interaction between Met4p and the F‐box protein Met30p occurs irrespective of the level of intracellular AdoMet, suggesting that the timing of Met4p degradation is not controlled by its interaction with the SCF Met30 complex. We also demonstrate that Met30p is a short‐lived protein, which localizes within the nucleus. Furthermore, transcription of the MET30 gene is regulated by intracellular AdoMet levels and is dependent upon the Met4p transcription activation function. Thus Met4p appears to control its own degradation by regulating the amount of assembled SCF Met30 ubiquitin ligase.