Interacts with TSPO (By similarity). Interacts with RIMS1 and RIMS2. Specifically expressed in brain. High expression level in the limbic system such as the nucleus accumbens, septum, and hippocampus, as well as on the cerebellum and pineal gland. Abundant in the CA1 region of the hippocampus. The second SH3 domain mediates binding to a proline-rich motif in RIMS1 and RIMS2. Belongs to the RIMBP family.