FIGURE 2.

Transcriptional induction of TMC1 by Rpn4. A, stress-induced transcription of TMC1 after treatment with sodium arsenite (1 mm) for the indicated times, as determined by RT-PCR analysis (upper panel). Lower panel, ribosomal RNA (loading control). B, schematic diagram of the TMC1 gene with its associated 5′-untranslated region. Two putative PACE motifs are shown with their locations indicated relative to the start codon. Both PACE elements show a canonical sequence (sometimes referred to as a type A motif; Ref. 16), identical to other well established Rpn4 targets such as RPT1 and RPN10. C, RT-PCR analysis of stress-induced transcription of TMC1 in response to sodium arsenite (1 mm for 1 h) in wild-type, rpn4Δ, yap1Δ, and yap8Δ strains, as indicated. Lower panel, ribosomal RNA (loading control). D, stress-induced up-regulation of Tmc1 protein is dependent on Rpn4. Whole cell extracts were prepared and analyzed by SDS-PAGE followed by immunoblot. Upper panel, anti-TAP antibody. Lower panel, anti-Pgk1 antibody (loading control). Sodium arsenite treatment was at 1 mm for 1 h.