Discs, Large Homolog Associated Protein 1 (DLGAP1)

DLGAP1 encodes the protein called guanylate kinase-associated protein (GKAP). GKAP binds to the SHANK and PSD-95 proteins fascilitating the assembly of the post synaptic density of neurons.Sequence analysis predicted that the 627-amino acid hydrophilic protein, which is 98% identical to the rat sequence, contains five 14-amino acid repeats in its N terminus. Binding analysis determined that the N-terminal region of DLGAP1 interacts with intact GK domains of all members of the DLG family, which share approximately 75% homology in the GK domain; DLGAP1 was found to interact less well with more distantly related MAGUKs. Immunoblot analysis showed expression of 95- and 130-kD DLGAP1 proteins in membranes from different regions of rat brain.