Mediates transcriptional and post-transcriptional regulation of SLC5A1. Inhibits a dynamin and PKC-dependent exocytotic pathway of SLC5A1. Also involved in transcriptional regulation of SLC22A2. Exhibits glucose-dependent, short-term inhibition of SLC5A1 and SLC22A2 by inhibiting the release of vesicles from the trans-Golgi network (By similarity). Interacts with YRDC. Localizes at the inner side of the plasma membrane. Nuclear localization in subconfluent LLC-PK1 cells is drastically decreased after cell confluence. Renal outer cortex and outer medulla, small intestine and liver.