Adaptor related protein complex 1 subunit sigma 3 (AP1S3)

Adaptor related protein complex 1 subunit sigma 3 (AP1S3) is a small, highly conserved subunit of the AP-1 clathrin-associated protein complex. AP1S3 mediates the recruitment of clathrin to cellular membranes and recognizes sorting signals on the cytosolic tails of transmembrane cargo proteins. Its primary biological role is in protein sorting in late-Golgi and endosomal compartments, influencing vesicular transport needed for normal cell function. AP1S3 is particularly important for trafficking innate immune receptors (such as TLR3) and regulating cytokine production, with mutations causing autoinflammatory skin diseases (notably generalized pustular psoriasis). Aberrant AP1S3 expression has also been implicated in tumor progression and viral life cycles, and it is being explored as a disease biomarker and therapeutic target in select conditions[1][2][3][4][6]. Note: No direct FDA-approved drugs currently target AP1S3, but its disease relevance makes it a candidate for future therapeutic development[1][3][6].

Other names

AP-1 complex subunit sigma-3Sigma1CAdaptor protein complex AP-1 subunit sigma-1CClathrin assembly protein complex 1 sigma-1C small chainGolgi adaptor HA1/AP1 adaptin sigma-1C subunitSigma 1C subunit of AP-1 clathrinPSORS15AP1S3 (gene symbol)

Not currently targeted directly by approved drugs. Theoretical mechanisms include modulation of endosomal trafficking, inhibition of cytokine signaling, or blocking clathrin-mediated transport pathways, particularly in the context of inflammation and possibly cancer