Molecular characterization of a novel human PDZ domain protein with homology to INAD from Drosophila melanogaster.

PDZ domains are thought to act as protein-binding modules mediating the clustering of membrane and membrane-associated proteins. The INAD protein has been shown to interact via a PDZ domain with the calcium channel TRP which contributes to capacitative calcium entry into Drosophila photoreceptor cells. We have cloned the cDNA of a human INAD-Like protein (hINADL) of 1524 amino acids in length containing at least five PDZ domains. Additionally, two truncated versions hINADL(delta304) and hINADL(delta853) were identified. hInadl transcripts of differing size are expressed in various tissues including brain, where transcripts are abundant in the cerebellum.