Signaling Complex Organization by PDZ Domain Proteins

As one of the most abundant protein domains in the genomes of metazoans, PDZ domains play important roles in the targeting of proteins to specific cell membranes, as well as assembling proteins into supramolecular signaling complexes. The structures of individual PDZ domains, along with their diverse cooccurrence with a great variety of other protein domains, provide the biochemical basis for the functional diversity of PDZ proteins. In this review, we first briefly summarize the structure and target-binding properties of PDZ domains. After surveying the SMART protein domain database, we attempt to classify PDZ domain proteins into three general categories. We end the review by presenting several recent studies showing some novel features of PDZ domain proteins.