Function
Together with sorf-2 negatively regulates the levels of phosphatidylinositol 3-phosphate (PtdIns3P) to enable the conversion of early endosomes to late endosomes. Binds to sorf-2 and the sorf-1-sorf-2 complex likely acts through bec-1, a non-catalytic subunit of phosphatidylinositol 3-kinase (PI3K), to suppress PI3K activity, thereby negatively regulating endosomal PtdIns3P levels.