FIGURE 2.

Defect in Sre1 cleavage in the absence of mga2 is amplified by positive feedback. A, Western blot, probed with monoclonal anti-Sre1 IgG (5B4) and polyclonal anti-Dsc5 IgG (for loading) and imaged by LI-COR Biosciences Odyssey CLx, of lysates treated with alkaline phosphatase for 1 h from WT, mga2Δ, or sre1Δ cells with WT or sre1-MP as indicated. Cells were grown for 0 or 4 h in the absence of oxygen. P and N denote precursor and cleaved N-terminal transcription factor forms, respectively. B, quantification from A of four biological replicates normalized for loading to Dsc5 and then normalized to maximum signal (WT N terminus band after treatment; lane 2) for comparison between blots. Error bars are 1 S.D. (**, p < 0.01 for N terminus by two-tailed Student's t test). Quantities of the precursor and nuclear form are stacked to give an approximation of total Sre1 signal per treatment.