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 (By similarity). Interacts with Ras family proteins. Localizes to midbody at telophase (By similarity). May shuttle between early and late endosomes. Does not colocalize with lysosomal markers. Constitutively expressed in brain, intestine and testis. Low constitutive expression, if any, in heart, lung, lymph nodes and thymus. Up-regulated in heart, kidney, liver, lymph nodes, spleen and thymus at day 20 after infection with Trypanosoma cruzi. Not detected in muscle. In vitro, up-regulated in peritoneal macrophages by GPI-mucins, bacterial lipopolysaccharides (LPS) and poly(I:C). Small induction, if any, by IFNG alone. Induction is maximal 12 and 18 hours following LPS stimulation (at protein level). Also induced in T-helper cells activated by phytohemagglutinin. In vivo, up-regulated by infection with protozoan parasites, including Plasmodium chabaudi and Trypanosoma cruzi. This induction is dependent upon IFNG, MYD88 and TICAM1.