Homer binds a novel proline-rich motif and links group 1 metabotropic glutamate receptors with IP3 receptors.
Group I metabotropic glutamate receptors (mGluRs) activate PI turnover and thereby trigger intracellular calcium release. Previously, we demonstrated that mGluRs form natural complexes with members of a family of Homer-related synaptic proteins. Here, we present evidence that Homer proteins form a physical tether linking mGluRs with the inositol trisphosphate receptors ... (IP3R). A novel proline-rich "Homer ligand" (PPXXFr) is identified in group 1 mGluRs and IP3R, and these receptors coimmunoprecipitate as a complex with Homer from brain. Expression of the IEG form of Homer, which lacks the ability to cross-link, modulates mGluR-induced intracellular calcium release. These studies identify a novel mechanism in calcium signaling and provide evidence that an IEG, whose expression is driven by synaptic activity, can directly modify a specific synaptic function.
Mesh Terms:
Amino Acid Sequence, Animals, Calcium, Calcium Channels, Carrier Proteins, Dynamins, GTP Phosphohydrolases, Gene Expression, Genes, Immediate-Early, Glutamic Acid, Inositol 1,4,5-Trisphosphate Receptors, Intracellular Membranes, Ligands, Molecular Sequence Data, Neuropeptides, Proline, Rats, Receptors, Cytoplasmic and Nuclear, Receptors, Metabotropic Glutamate, Time Factors
Amino Acid Sequence, Animals, Calcium, Calcium Channels, Carrier Proteins, Dynamins, GTP Phosphohydrolases, Gene Expression, Genes, Immediate-Early, Glutamic Acid, Inositol 1,4,5-Trisphosphate Receptors, Intracellular Membranes, Ligands, Molecular Sequence Data, Neuropeptides, Proline, Rats, Receptors, Cytoplasmic and Nuclear, Receptors, Metabotropic Glutamate, Time Factors
Neuron
Date: Oct. 01, 1998
PubMed ID: 9808459
View in: Pubmed Google Scholar
Download Curated Data For This Publication
4432
Switch View:
- Interactions 2