Enables several functions, including SH3 domain binding activity; guanyl-nucleotide exchange factor activity; and phosphatidylinositol-3-phosphate binding activity. Involved in endocytic recycling and positive regulation of GTPase activity. Acts upstream of or within synaptic vesicle endocytosis. Located in several cellular components, including clathrin-coated vesicle membrane; dendrite; and neuronal cell body. Orthologous to human DENND1A (DENN domain containing 1A). [provided by Alliance of Genome Resources, Apr 2022]