Adaptor related protein complex 2 subunit sigma 1 (AP2S1)

Adaptor related protein complex 2 subunit sigma 1 (AP2S1) encodes the small sigma subunit of the AP-2 adaptor complex, a heterotetramer involved in clathrin-mediated endocytosis at the plasma membrane[1][4][6]. AP-2 is responsible for cargo selection and assembly of clathrin-coated vesicles, recognizing specific endocytic motifs in transmembrane cargo molecules[1][2][4][8]. AP2S1 is directly implicated in receptor-mediated endocytosis and the recycling of synaptic vesicle membranes, and may play a role in extracellular calcium homeostasis[2][8]. Mutations in AP2S1, particularly at residue Arg15, cause familial hypocalciuric hypercalcemia type 3, a genetic disorder disrupting calcium homeostasis due to impaired calcium-sensing receptor trafficking[2][8]. No drugs are currently known to directly target AP2S1; its fundamental cellular role suggests therapeutic targeting would present challenges related to disruption of essential trafficking mechanisms[2][4][8].

Other names

AP-2 complex subunit sigmaAP17CLAPS2FBH3FBHOkHHC3Sigma2-adaptinsigma-2Clathrin assembly protein 2 sigma small chainClathrin coat assembly protein AP17Clathrin coat-associated protein AP17Plasma membrane adaptor AP-2 17 kDa proteinHA2 17 kDa subunitClathrin-associated protein small 2

Not established for any current therapeutics; theoretical mechanisms may involve modulation of endocytosis or calcium-sensing receptor trafficking[2].