CRIPT, also known as cysteine-rich PDZ-binding protein, belongs to the CRIPT family. It interacts with TUBB1. CRIPT also interacts strongly with the PDZ3 domain of members of the DLG4 family. It is involved in the cytoskeletal anchoring of DLG4 in excitatory synapses. CRIPT is highly conserved from mammals to plants and binds selectively to the third PDZ domain (PDZ3) of PSD-95 via its C terminus. n heterologous cells, CRIPT causes a redistribution of PSD-95 to microtubules. In brain, CRIPT colocalizes with PSD-95 in the postsynaptic density and can be coimmunoprecipitated with PSD-95 and tubulin. These findings suggest that CRIPT may regulate PSD-95 interaction with a tubulin-based cytoskeleton in excitatory synapses.