May play a role as a localized scaffold for the assembly of a multiprotein signaling complex and as mediator of the trafficking of its binding partners at specific subcellular location in neurons. Interacts with EFNB1, EFNB3, GRIA2, GRIA3, CSPG4 and GRIPAP1. Can form homomultimers and heteromultimers with GRIP1 (By similarity). Interacts with the C-terminal tail of PRLHR. PDZ 5 mediates the C-terminal binding of GRIA2 and GRIA3. PDZ 6 mediates interaction with the PDZ recognition motif of EFNB1. PDZ 7 mediates interaction with CSPG4 (By similarity). Due to intron retention. Belongs to the GRIP2 family. Extended N-terminus. Probable cloning artifact.