Fig. 6: The phosphorylation of the DLX3 NLS by MAST4 regulates the activation of target genes involved in pH regulation.

a 3xDRE-luc, DLX3, and HA-MAST4-Full were transiently overexpressed in HEK293T cells, and beta-galactosidase was cotransfected for normalization. Luciferase activities were measured after 48 h. b–f DLX3^WT, DLX3^AAA, and HA-MAST4 PDZ were transiently transfected into HEK293T cells. ChIP assays showed that transfection of DLX3^WT increased target gene promoter binding and that HA-MAST4 PDZ cotransfection further increased target gene promoter binding, whereas transfection of DLX3^AAA had no significant effect. b–d Carbonic anhydrases. e, f Ion transporters. g RT‒qPCR results for carbonic anhydrases and ion transporters involved in pH regulation. mHat9d cells were transiently transfected with DLX3^WT, DLX3^AAA, and HA-MAST4-Full. The data were presented as the means ± SDs (n = 3 for a–g). *p < 0.05; **p < 0.01; ns nonsignificant.