| The family members , SALM 1 SALM4 , have a single transmembrane ( TM ) domain and contain extracellular leucine rich repeats , an Ig C 2 type domain , a fibronectin type 3 domain , and an intracellular postsynaptic density 95 ( PSD 95 ) / Discs large / zona occludens 1 ( PDZ ) binding domain , which is present on all members except SALM 4 . ^^^ SALM 1 interacts with PSD 95 , synapse associated protein 102 ( SAP 102 ) , and SAP 97 based on coimmunoprecipitation of detergent solubilized brain . ^^^ Overexpression of SALM 1 in 14 DIV neurons recruits NMDA receptors ( NR ) and PSD 95 to dendritic puncta . ^^^ |