Melanocyte protein PMEL (Glycoprotein 100) (gp100)

Glycoprotein 100 (gp100/PMEL/Pmel17) is a glycosylated transmembrane protein specific to melanocytes, critical for melanosome maturation and melanin deposition. In cancer, especially melanoma, gp100 functions as a tumor-associated antigen. Fragments of gp100 are processed by the antigen presentation pathways and displayed on MHC class I or II molecules. These epitopes are recognized by cytotoxic T lymphocytes, enabling immune targeting of tumor cells. Clinically, gp100 is targeted by peptide vaccines, dendritic cell therapies, and, notably, tebentafusp—a bispecific fusion protein approved for uveal melanoma. The gp100 antigen is also used as a diagnostic marker with antibodies such as HMB-45. Expression is largely confined to cells of the melanocytic lineage and most melanoma tumors, making it a selective therapeutic and diagnostic target.

Other names

Glycoprotein 100PMELPmel17Silver protein

T cell recruitment/activation: ImmTAC molecules like tebentafusp recruit and activate T cells against melanoma cells expressing gp100. Vaccine approaches: Peptide vaccines elicit cytotoxic T lymphocyte responses to gp100-expressing tumor cells.