Guanine nucleotide exchange factor (GEF) with specificity for RAP2A, it doesn't seems to activate other Ras family proteins (in vitro). Interacts with CCDC124 during cytokinesis. Interacts with Ras family proteins (By similarity). Localizes to midbody at telophase (By similarity). Localizes to midbody at telophase (By similarity). May shuttle between early and late endosomes. Does not colocalize with lysosomal markers (By similarity).