Fig. 4
From: Identification and characterization of sugar-regulated promoters in Chaetomium thermophilum
Characterization of carbon-regulated promoters in YFP-reporter strains. Promoter regions from selected glucose-repressed and xylose-activated genes were characterized in YFP-reporter strains. The promoter-YFP-expressing reporter strains were subjected to the induction assay shown in Fig. 2. In essence, reporter strains were grown in glucose-containing medium for 16 h and subsequently shifted to glucose-containing or xylose-containing medium for up to 8 h. Samples were taken before medium exchange (0 h) and at the indicated time points after medium exchange for fluorescence microscopy and immunoblotting against the YFP. YFP expression is shown for PCBP (a), PXYL (b) and PXDH (c). Because no antibody is available for normalization purposes, we loaded equal amounts of protein, as shown by ponceau S (PS) staining. Note that lysates from cultures grown in glucose and xylose were analysed on the same membrane. Exposure times for the Western blot had to be adjusted according to the level of expression of the respective promoter, as follows: PCBP (5 min), PXYL (1 s), PXDH (10 s). Exposure times were identical for Glu- and Xyl-derived samples. Unprocessed blots/gels are presented in Supplementary Fig. 7