Discs, Large Homolog Associated Protein 3 (DLGAP3)

Using a segment of rat Fak (PTK2) to screen an adult human brain cDNA library, Bongiorno-Borbone et al. (2005) cloned DLGAP3, which they called SAPAP3. The deduced protein contains 977 amino acids. By Northern blot analysis, Takeuchi et al. (1997) found brain-specific expression of rat Sapap3. The rat protein localized to dendrites and cell bodies and was enriched in synaptosomal membrane fractions.By mutation analysis, Bongiorno-Borbone et al. (2005) demonstrated that the N-terminal half of human SAPAP3 interacted with a C-terminal segment of rat Fak. They also found that SAPAP3 interacted with Pyk2 (PTK2B) in in vitro pull-down assays. In rat forebrain lysates, part of Fak and Pyk2 had a similar subcellular distribution as Sapap3 and Sap90/Psd95, which supported their functional association.