Adaptor protein complex 1 subunit sigma-1A (AP1S1)

Adaptor protein complex 1 subunit sigma-1A (AP1S1) is a small subunit of the adaptor protein complex-1 (AP-1), a heterotetrameric complex involved in the formation of clathrin-coated vesicles and essential for cargo selection, membrane trafficking, and protein sorting between the trans-Golgi network, endosomes, and the plasma membrane. AP1S1 is required for proper vesicular transport, impacting intracellular trafficking, immune response regulation, and is associated with disease processes including inherited disorders (such as MEDNIK syndrome, characterized by a combination of mental retardation, enteropathy, deafness, neuropathy, ichthyosis, and keratoderma) and cancer (notably acting as a potential oncogene in breast cancer). Mutations in AP1S1 disrupt protein trafficking and epithelial barrier function; overexpression has been linked to poor outcomes in breast cancer, likely through altered vesicle-mediated signaling and reduced immune cell infiltration. Key points: - Adaptor protein, not a classical therapeutic target such as receptor, enzyme, or transporter. - Central to vesicular transport and clathrin-mediated endocytosis. - No approved or well-characterized drugs directly targeting AP1S1. - Potential biomarker and mechanistic role in breast cancer prognosis; causal in certain rare genetic diseases.

Other names

AP-1 complex subunit sigma-1AAP1S1AP19CLAPS1SIGMA1AAdaptor protein complex AP-1 subunit sigma-1AAdaptor-related protein complex 1 subunit sigma-1AClathrin assembly protein complex 1 sigma-1A small chainClathrin coat assembly protein AP19Golgi adaptor HA1/AP1 adaptin sigma-1A subunitHA1 19 kDa subunitSigma1A-adaptinclathrin-associated/assembly/adaptor protein, small 1 (19kD)EKV3MEDNIKWUGSC:H_DJ0747G18.2Sigma-Adaptin 1ASigma 1a subunit of AP-1 clathrin adaptor complex