FIGURE 8: Either Med13 degron is sufficient for Med13 degradation. (A) med13∆ (RSY1701) cells harboring either Med13^{571-650deg∆-}HA (pKC805, upper panels) or Med13^{742-844deg∆-}HA plasmids (pKC814, lower panels) were treated with 0.4 mM H₂O₂ for the timepoints indicated and Med13^deg∆-HA levels analyzed by Western blot. Tub1 levels were used as a loading control. (B) Degradation kinetics of the results shown in (A). Values represent averages ± SD from a total of at least two Western blots from independent experiments. For clarity, the degradation kinetics of wild-type Med13-HA from previous experiments was included. (C) Model depicting how two SCF^Grr1 phospho-degrons mediate the destruction of Med13 following H₂O₂ stress. In unstressed cells cyclin C-Cdk8 phosphorylates degron^742-844 [9] but both degrons are protected by an unknown mechanism from Snf1 and Slt2 kinase activity (depicted by the red circle). Following H₂O₂ stress Snf1 and Slt2 are activated and permitted access to the now exposed degrons. This results in SCF^Grr1 mediated degradation of Med13 and cyclin C nuclear release (not shown).

9. Stieg DC, Willis SD, Ganesan V, Ong KL, Scuorzo J, Song M, Grose J, Strich R, Cooper KF (2018). A complex molecular switch directs stress-induced cyclin C nuclear release through SCF(Grr1)-mediated degradation of Med13. Mol Biol Cell 29(3): 363-375. http://dx.doi.org/10.1091/mbc.E17-08-0493