HOMER3

This gene encodes a member of the HOMER family of postsynaptic density scaffolding proteins that share a similar domain structure consisting of an N-terminal Enabled/vasodilator-stimulated phosphoprotein homology 1 domain which mediates protein-protein interactions, and a carboxy-terminal coiled-coil domain and two leucine zipper motifs that are involved in self-oligomerization. The encoded protein binds numerous other proteins including group I metabotropic glutamate receptors, inositol 1,4,5-trisphosphate receptors and amyloid precursor proteins and has been implicated in diverse biological functions such as neuronal signaling, T-cell activation and trafficking of amyloid beta peptides. Alternative splicing results in multiple transcript variants.[provided by RefSeq, Mar 2009]

Full Name

homer scaffold protein 3

Function

Postsynaptic density scaffolding protein. Binds and cross-links cytoplasmic regions of GRM1, GRM5, ITPR1, DNM3, RYR1, RYR2, SHANK1 and SHANK3. By physically linking GRM1 and GRM5 with ER-associated ITPR1 receptors, it aids the coupling of surface receptors to intracellular calcium release. Isoforms can be differently regulated and may play an important role in maintaining the plasticity at glutamatergic synapses. Negatively regulates T cell activation by inhibiting the calcineurin-NFAT pathway. Acts by competing with calcineurin/PPP3CA for NFAT protein binding, hence preventing NFAT activation by PPP3CA (PubMed:18218901).

Biological Process

G protein-coupled glutamate receptor signaling pathway Source: GO_Central
Negative regulation of calcineurin-NFAT signaling cascade Source: UniProtKB
Negative regulation of interleukin-2 production Source: UniProtKB
Protein targeting Source: UniProtKB
Regulation of store-operated calcium entry Source: GO_Central

Cellular Location

Cytoplasm; Postsynaptic density; Synapse. Postsynaptic density of neuronal cells.