PDZ Domain Containing Protein 4 (PDZD4)

PDZD4 protein contains a bipartite nuclear localization signal and a PDZ domain. The PDZD4 protein shares 93% sequence identity with the mouse ortholog and 49.9% sequence identity with PDZRN4 alternative splice form PDZRN4S.The deduced PDZD4 proteins encoded by the variants are 673 (Adult1), 769, and 660 amino acids long; however, in vitro translation studies and expression in COS-7 cells showed translation of the 769- (Fetal1/SS) and 660-amino acid (Adult2/Fetal2) variants only. Both the deduced Fetal1/SS and Adult2/Fetal2 PDZD4 variants have a predicted N-terminal PDZ domain with an additional N-terminal PDZ domain predicted for the Fetal/SS variant. Northern blot analysis detected 4.5- and 3.8-kb transcripts in adult brain and 4.2- and 3.8-kb transcripts in fetal brain.