HOMER1

This gene encodes a member of the homer family of dendritic proteins. Members of this family regulate group 1 metabotrophic glutamate receptor function. [provided by RefSeq]

Full Name

homer homolog 1 (Drosophila)

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. May also couple GRM1 to PI3 kinase through its interaction with AGAP2. Isoform 1 regulates the trafficking and surface expression of GRM5. Isoform 3 acts as a natural dominant negative, in dynamic competition with constitutively expressed isoform 1 to regulate synaptic metabotropic glutamate function. Isoform 3, may be involved in the structural changes that occur at synapses during long-lasting neuronal plasticity and development. Forms a high-order complex with SHANK1, which in turn is necessary for the structural and functional integrity of dendritic spines (By similarity).

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

Behavioral response to cocaine Source: Ensembl
Chemical homeostasis within a tissue Source: Ensembl
Chemical synaptic transmission Source: ProtInc
Circadian rhythm Source: Ensembl
G protein-coupled glutamate receptor signaling pathway Source: GO_Central
Phospholipase C-activating G protein-coupled glutamate receptor signaling pathway Source: ProtInc
Positive regulation of calcium ion transport Source: Ensembl
Positive regulation of signal transduction Source: BHF-UCL
Protein localization to synapse Source: Ensembl
Protein tetramerization Source: UniProtKB
Regulation of calcium ion import Source: Ensembl
Regulation of cation channel activity Source: BHF-UCL
Regulation of dendritic spine maintenance Source: UniProtKB
Regulation of postsynaptic neurotransmitter receptor activity Source: Ensembl
Regulation of store-operated calcium entry Source: GO_Central
Regulation of synaptic transmission, glutamatergic Source: UniProtKB
Response to calcium ion Source: BHF-UCL
Response to nicotine Source: Ensembl
Skeletal muscle contraction Source: Ensembl
Skeletal muscle fiber development Source: Ensembl

Cellular Location

Cytoplasm; Postsynaptic density; Synapse; Dendritic spine. Isoform 1 inhibits surface expression of GRM5 causing it to be retained in the endoplasmic reticulum.