Multifunctional protein that functions as a downstream effector of RALA and RALB. As a GTPase-activating protein/GAP can inactivate CDC42 and RAC1 by stimulating their GTPase activity. As part of the Ral signaling pathway, may also regulate ligand-dependent EGF and insulin receptors-mediated endocytosis. During mitosis, may act as a scaffold protein in the phosphorylation of EPSIN/EPN1 by the mitotic kinase cyclin B-CDK1, preventing endocytosis during that phase of the cell cycle. During mitosis, also controls mitochondrial fission as an effector of RALA. Recruited to mitochondrion by RALA, acts as a scaffold to foster the mitotic kinase cyclin B-CDK1-mediated phosphorylation and activation of DNM1L.; Could also function as a primary ATP-dependent active transporter for glutathione conjugates of electrophiles. May also actively catalyze the efflux of a wide range of substrates including xenobiotics like doxorubicin (DOX) contributing to cell multidrug resistance.