Figure 5.
The interactions between YWHA/14-3-3 proteins and TFEB are essential for TFEB subcellular localization. (a) Subcellular distribution of TFEB and its mutants under nutrient-rich and starvation conditions. Under nutrient-rich conditions, wild-type TFEB is largely distributed in the cytoplasm. The TFEB mutants (S209A, S211A, P213A, A214Q and L216Q) showed increased nuclear localization, whereas the TFEBT208R mutant did not. Upon starvation, wild-type TFEB and the TFEB mutants are mainly localized in the nucleus. Scale bar: 50 μm. (b) Quantification of the subcellular distribution data shown in panel A. The percentage of the fluorescence intensity of each construct in the nucleus was quantified (average of 4 experiments, n > 50 cells for each experiment). Each bar represents the mean ±SD, **p < 0.01, *p < 0.05. (c) A schematic model illustrating the YWHA/14-3-3-mediated regulation of TFEB subcellular localization. Briefly, the binding of YWHA/14-3-3 proteins could induce the conformational changes of the p-S211-site and the region between the NLS and the p-S211-site, which would potentially interfere with the NLS. The structural model was built based on the structures of the bHLH domain of MITF (PDB: 4ATH) and the YWHA-p-S211-peptide complex.