Plays a role in regulation of vesicular cargo transport from the trans-Golgi network (TGN) to the plasma membrane . Regulates Golgi phosphatidylinositol 4-phosphate (PtdIns(4)P) levels and activates the PtdIns(4)P phosphatase activity of SACM1L when it binds PtdIns(4)P in 'trans' configuration . Binds preferentially to PtdIns(4)P (, ). Negatively regulates APOB secretion from hepatocytes .
Subcellular locations: Golgi apparatus, Trans-Golgi network membrane
Localizes to ER-trans Golgi network (TGN) contacts sites.
Widely expressed.