Component of a complex required to localize phosphatidylinositol 4-kinase (PI4K) to the plasma membrane. The complex acts as a regulator of phosphatidylinositol 4-phosphate (PtdIns(4)P) synthesis (By similarity). In the complex, plays a central role in bridging PI4KA to EFR3B and FAM126A, via direct interactions (By similarity). Component of a phosphatidylinositol 4-kinase (PI4K) complex, composed of PI4KA, EFR3 (EFR3A or EFR3B), TTC7 (TTC7A or TTC7B) and FAM126 (FAM126A or FAM126B) (By similarity). Interacts with PI4KA, interaction is direct (By similarity). Interacts with EFR3 (EFR3A or EFR3B), interaction is direct (By similarity). Interacts with FAM126 (FAM126A or FAM126B), interaction is direct (By similarity). Association with the PI4K complex is strongly reduced by TMEM150A (By similarity). Localizes to the cytosol and is recruited to the plasma membrane following interaction with EFR3 (EFR3A or EFR3B).