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. Highly expressed in renal outer medulla, renal inner medulla, duodenum, ileum and jejunum. Moderately expressed in renal outer cortex, renal papilla, brain and liver.