Transporter associated with antigen processing 1 (TAP1)

Transporter associated with antigen processing 1 (TAP1) is a critical component of the adaptive immune system, forming a heterodimeric complex with TAP2 to transport cytosolic peptides into the endoplasmic reticulum (ER) for loading onto MHC class I molecules. This transport is essential for the subsequent presentation of antigens on the cell surface, allowing cytotoxic T lymphocytes to recognize and eliminate infected or malignant cells. In various cancers and viral infections, TAP1 is frequently downregulated or functionally inhibited as a mechanism of immune evasion, leading to reduced antigen presentation and escape from immune surveillance. While no small-molecule drugs are currently approved to directly target TAP1, therapeutic strategies such as interferon-gamma treatment or gene therapy are explored to restore its expression and enhance anti-tumor immunity. Conversely, many viruses, including cytomegalovirus and herpes simplex virus, produce specialized proteins that specifically bind and inhibit TAP1 to avoid detection by the host immune system.

Other names

Antigen peptide transporter 1ABCB2ATP-binding cassette sub-family B member 2ABC17APT1PSF-1RING4

Facilitates the ATP-dependent transport of peptides from the cytosol into the endoplasmic reticulum lumen for loading onto MHC class I molecules; its inhibition prevents antigen presentation to cytotoxic T cells.