FunctionAdapter 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.
Tissue specificityUbiquitous. Isoform 1 is the predominant isoform. Weak level of isoform 2 is present in all tested tissues, except in liver and heart where it is highly expressed.
Sequence similaritiesBelongs to the syntrophin family. Contains 1 PDZ (DHR) domain. Contains 2 PH domains. Contains 1 SU (syntrophin unique) domain.
DomainThe PH 1 domain mediates the oligomerization in a calcium dependent manner. The PDZ domain binds to the last three or four amino acids of ion channels and receptor proteins. The association with dystrophin or related proteins probably leaves the PDZ domain available to recruit proteins to the membrane. The SU domain binds calmodulin in a calcium-dependent manner.
Post-translational modificationsPhosphorylated. Partially dephosphorylated upon insulin stimulation.
Cellular localizationMembrane. Cytoplasmic vesicle > secretory vesicle membrane. Cell junction. Cytoplasm > cytoskeleton. Membrane-associated. In muscle, it is exclusively localized at the neuromuscular junction (By similarity). In insulinoma cell line, it is enriched in secretory granules.