Required for optimal lysosomal function . Blocks EGF-stimulated EGFR intraluminal sorting and degradation. Conversely by binding with the phosphatidylinositol 4,5-bisphosphate, regulates its PIP5K1C interaction, inhibits HGS ubiquitination and relieves LAPTM4B inhibition of EGFR degradation . Recruits SLC3A2 and SLC7A5 (the Leu transporter) to the lysosome, promoting entry of leucine and other essential amino acid (EAA) into the lysosome, stimulating activation of proton-transporting vacuolar (V)-ATPase protein pump (V-ATPase) and hence mTORC1 activation . Plays a role as negative regulator of TGFB1 production in regulatory T cells . Binds ceramide and facilitates its exit from late endosome in order to control cell death pathways .
Endomembrane system ; Multi-pass membrane protein . Late endosome membrane . Cell membrane . Cell projection . Lysosome membrane . Endosome membrane. Endosome, multivesicular body membrane . Endosome, multivesicular body lumen .