TM9SF4

Associates with proteins harboring glycine-rich transmembrane domains and ensures their efficient localization to the cell surface. Regulates the assembly and activity of V-ATPase in colon cancer cells via its interaction with V-type proton ATPase subunit H (ATP6V1H) and contributes to V-ATPase-mediated pH alterations in cancer cells which play an important role in drug resistance and invasiveness of colon cancer cells. Plays an important role in an atypical phagocytic activity of metastatic melanoma cells called cannibalism and is involved in the pH regulation of the intracellular vesicles in tumor cells..

Function from UniProtKB (Q92544), read 2026-09-23. CC BY 4.0.