Isolation of PSD‐Zip45, a novel Homer/vesl family protein containing leucine zipper motifs, from rat brain1

Abstract
Using monoclonal antibody against the 45 kDa postsynaptic density protein, we isolated a novel isoform of Homer/vesl. The NH2‐terminal region containing a PDZ domain of this protein is identical to that of Homer/vesl, and the COOH‐terminal region containing unique leucine zippers shows self‐multimerization. We named this protein PSD‐Zip45. In addition to specific binding of PSD‐Zip45 mediated by a PDZ domain to the metabotropic glutamate receptors 1α or 5, the distribution of PSD‐Zip45 transcripts is highly consistent with that of metabotropic glutamate receptor transcripts. The PSD‐Zip45 is, therefore, the first candidate as receptor anchoring proteins containing leucine zipper motifs in the central nervous system.