Figure 3. Effects of mutations (K¹⁷¹R¹⁷²R¹⁷³I¹⁷⁴) on the major binding-site of NLS on transcriptional activity and nuclear localization of ChREBP.

(A) Transcriptional activity of DNA constructs expressing the indicated FLAG-ChREBP proteins using firefly luciferase under control of LPK promoter, and Renilla luciferase (an internal control) were co-transfected into HepG2 cells during a 4-h incubation in DMEM containing 5.5 mM glucose. Fresh medium containing 27.5 mM glucose was added and the cells were incubated for an additional 20 h. Luciferase activities were measured and expressed as firefly luciferase activity relative to Renilla luciferase activity. The values presented are the mean ± S.D. of the results of eight independent experiments. * P < 0.05; *** P < 0.001. (B) Nuclear localization of ChREBP in HepG2 cells. HepG2 cells were transfected with DNA constructs expressing GFP-WT ChREBP or indicated GFP-ChREBP mutants during a 4 h incubation in DMEM with 5.5 mM glucose. Fresh medium containing 27.5 mM glucose was added, and the cells were incubated an additional 20 h. The values presented are the means ± S.D. of four sets of 100 fluorescent cells. * P < 0.05; ** P < 0.01; *** P < 0.001.