Proposed effector of Rab5. Binds to phosphatidylinositol 3-phosphate (PI(3)P). Involved in homotypic early endosome fusion and to a lesser extent in heterotypic fusion of chlathrin-coated vesicles with early endosomes. Involved in macropinocytosis; the function is dependent on Rab5-GTP. Required for correct endosomal localization. Involved in the internalization and trafficking of activated tyrosine kinase receptors such as PDGFRB. Regulates the subcellular localization of the retromer complex in a EHD1-dependent manner. Involved in endosome-to-Golgi transport and biosynthetic transport to late endosomes and lysosomes indicative for a regulation of retromer complex-mediated retrograde transport. Interacts with RAB5A (in GTP-bound form). Interacts with RHOD (independent of GTP-loaded status). Interacts with EHD1. Interacts with VPS26A; the interaction is independent of EHD1 and is indicative for an association with the cargo recognition subcomplex of the retromer complex. Also associated with endosomal membranes. Localizes to macropinosomes. High expression in whole adult brain and intermediate expression in all other tissues and specific brain regions examined, including fetal brain. Intron retention. Extended N-terminus.