Suppresses cannabinoid receptor CNR1-mediated tonic inhibition of voltage-gated calcium channels. Interacts with the cannabinoid receptor CNR1 (via C-terminus). Does not interact with cannabinoid receptor CNR2 (By similarity). Highly expressed in brain. Also detected in heart, lung, intestine, kidney, testis, spleen, liver and muscle (at protein level). Belongs to the CNRIP family.