Adapter protein that binds to and probably organizes the subcellular localization of a variety of membrane proteins. May link various receptors to the actin cytoskeleton and the dystrophin glycoprotein complex. May play a role in the regulation of secretory granules via its interaction with PTPRN. This is the function of SNTB2 (syntrophin beta 2, Ensembl gene identifier ENSG00000168807).