Regulates intracellular concentrations of taurine and glutamate (Ref.5). Negatively modulates SLC1A1/EAAC1 glutamate transport activity by decreasing its affinity for glutamate in a PKC activity-dependent manner (PubMed:11242046). Plays a role in the retention of SLC1A1/EAAC1 in the endoplasmic reticulum (PubMed:19720795). Homodimer. Heterodimer with ARL6IP1 (By similarity). Forms multimers (PubMed:11242046). Interacts with ARL6 (By similarity). Interacts with prenylated RAB1A and RAB3A (PubMed:11096102). Interacts with SLC1A1/EAAC1 (PubMed:11242046). Interacts with RTN2 (via first transmembrane domain) (PubMed:19720795). Does not interact with VAMP1, VAMP2 or VAMP3 (PubMed:11096102). Also exists as a soluble form in the cytoplasm (PubMed:11242046). Associated with microtubules (Ref.5). Ubiquitous (PubMed:11096102). Most abundant in heart and brain (PubMed:11096102). In the embryonic brain cortex, expressed in neurons and astrocytes (PubMed:19720795). By methyl-beta-cyclodextrin. Belongs to the PRA1 family.