FIG 2 .

Fbx23 and Fbx47 are involved in the secretion of extracellular proteins. (A) Expression of xlnA in the WT (wild-type), Δfbx23, and Δfbx47 strains when grown in MM (minimal medium) supplemented with 1% fructose for 24 h (control) and after transfer to MM supplemented with 1% xylose [derepressing; (X)] or 1% xylose plus 2% glucose [repressing; (G + X)] for 30, 60, and 120 min. (B) Extracellular xylanase activity under the same conditions as those described for panel A, although at later time points (12, 24, 48, and 72 h). (C and D) Silver-stained gel of secreted proteins of 3 biological replicates in the WT strain and Δfbx23 (C) and Δfbx47 (D) strains after transfer from fructose-rich to xylose-rich MM for 72 h. Also shown is the total protein concentration for each sample as measured by Bradford assay. Standard deviations represent the average results from 3 biological replicates; statistical differences were calculated using a paired t test (*, P < 0.05, **, P < 0.01; ***, P < 0.001) based on comparison with the WT strain.