FIGURE 3: Kdx1 and Slt2 promote cyclin C relocalization and destruction in response to 1.2 mM H₂O₂ stress.

(A) Cyclin C levels were monitored as described previously in wild type (RSY10), slt2∆ kdx1∆ (RSY1737), slt2∆ (RSY1006) and kdx1∆ (RSY1736) strains exposed to 1.2 mM H₂O₂ for the times indicated. Tub1 levels were used as a loading control.

(B) Quantification of the results obtained in (A).

(C) Cyclin C remains perinuclear in the slt2∆ kdx1∆ strain following 1.2 mM H₂O₂ stress. Fluorescence microscopy was conducted on mid-log phase on slt2∆ kdx1∆ cells expressing YFP-cyclin C (pBK37) following (2 h) 1.2 mM H₂O₂ treatment. The cells were fixed, stained with DAPI and then examined by fluorescence microscopy. Representative images (collapsed deconvolved 0.2 µm slices) of the results obtained are shown.

(D) Quantification of the results in C. The percent of the population displaying at least 3 cyclin C-YFP foci in the cytoplasm is given (mean ± s.e.m.). At least 200 cells were counted per time point from 3 individual isolates.