Homer as both a scaffold and transduction molecule.
Increasing evidence shows that scaffold proteins not only control membrane assembly of receptors and channels, but also modulate intracellular signaling by assembled receptors. The Homer family of proteins act as scaffolds to bind clusters of proteins and glutamate receptors at postsynaptic sites. We review results of cloning and gene expression of this protein family, and summarize roles in glutamate receptor function and intracellular signaling in neurons. Homer proteins trigger the localization of metabotropic glutamate receptor subtype 5 (mGlu5 receptor) to the postsynaptic plasma membrane. They can also alter the kinetics and peak amplitude of the intracellular Ca2+ responses of mGlu1 and mGlu5 receptors. Homer proteins can either prevent or promote spontaneous activation of these receptors, depending on the type of Homer protein isoform expressed.
Fagni
Laurent
L
UPR CNRS 9023, CCIPE, 141 Rue de la Cardonille, 34094 Montpellier, France. fagni@montp.inserm.fr
Worley
Paul F
PF
Ango
Fabrice
F
D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D000072233:Homer Scaffolding Proteins; D006801:Humans; D009479:Neuropeptides / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
D002352:Carrier Proteins; D000072233:Homer Scaffolding Proteins; D009479:Neuropeptides