Cysteine Rich PDZ Binding Protein (CRIPT)

Human CRIPT shares 99% amino acid sequence identity with rat Cript, 68% identity with the A. thaliana homolog, and 48% identity with the C. elegans homolog. The greatest conservation is found in the N- and C-terminal regions, which contain several cys-X-X-cys repeats. The authors demonstrated that Cript binds selectively to the PDZ3 domain of Psd95 via its C terminus. Northern blot analysis of rat tissues detected 2 major Cript transcripts in all tissues examined, namely brain, heart, spleen, lung, liver, skeletal muscle, kidney, and testis; the 2 transcripts may contain different 3-prime untranslated regions. Immunohistochemical analysis showed that Cript is widespread but differentially expressed in rat brain. It was expressed prominently in the hippocampus, moderately in the striatum and cortex, and modestly in the midbrain.