SDCBP is a multifunctional intracellular adapter protein. SDCBP protein has tandemly repeated PDZ domains which react with the FYA （phe-tyr-ala） carboxyterminal amino acid sequence of the syndecans. SDCBP is has a role in organization of protein complexes in the plasma membranes， regulation of B-cell development， activation of transcription factors， intracellular trafficking and cell-surface targeting， synaptic transmission， and axonal outgrowth.
