Homer protein homolog 2 (HOMER2)

Binds and cross-links cytoplasmic areas of GRM1, GRM5, ITPR1, DNM3, RYR1, RYR2, SHANK1 and SHANK3. By physically linking GRM1 and GRM5 with ER-associated ITPR1 receptors, it helps the coupling of surface receptors to intracellular calcium release.

May also couple GRM1 to PI3 kinase through its interaction with AGAP2. Isoforms can be otherwise regulated and might play an important role in maintaining the plasticity at glutamatergic synapses (PubMed:9808459).