BART binds specifically to ARL2.GTP with a high affinity however it does not bind to ARL2.GDP. It is thought that this specific interaction is due to BART being the first identified ARL2-specific effector. The function is not completely characterized. BART is predominantly cytosolic but can also be found to be associated with mitochondria. BART is also involved in binding to the adenine nucleotide transporter ANT1.