HOMER1: Proteins and Enzymes

HOMER1 is a 48 kDa cytoplasmic protein that regulates the cell surface localization of neuronal mGluR1 and mGluR5 metabotropic glutamate receptors. It also functions in striated muscle mechanotransduction and excitation-contraction coupling by regulating the localization of transient receptor potential (TRP) channels and the coupling of ryanodine receptors to Cav1.2 calcium channels. Alternately spliced isoforms of human HOMER1 lack either the C-terminal half of the molecule (aa 178 - 354) or 130 aa following the WH1 domain (aa 99-228). Particular isoforms show distinct effects on hippocampal neuronal plasticity and the maintenance of extracellular glutamate levels in the prefrontal cortex.