ADP-ribosylation factor-like protein 2 (ARL2) is a small (21kDa) GTPase protein that is able to bind GDP or GTP. It is implicated in a range of processes from trafficking processes to regulation of microtuble dynamics. ADP-ribosylation factor-like protein 2-binding protein (ARL2BP aka BART) is an effector protein that binds ARL2 (Zhang et al. 2009, Bailey et al. 2009). This binding is dependent on ARL2 being in its GTP-bound form.