Melanoma Associated ME20 (ME20M)

Melanocytes preferentially express an mRNA species, PMEL17, whose protein product crossreacts with antityrosinase antibodies and whose expression correlates with the melanin content.Maresh et al. (1994) cloned the gene encoding ME20, a melanoma-associated antigen. The cDNA encodes a 661-amino acid precursor with a 23-residue signal peptide and a 26-residue N-terminal transmembrane domain. The transmembrane domain is followed by a C-terminal 45-amino acid putative intracellular domain rich in serine residues. Signal peptide cleavage results in a 637-residue membrane-associated protein, designated ME20-M. ME20-M is derived from a 3.3- to 3.4-kb transcript expressed at varying levels in melanoma cell lines. The ME20-M protein has a deletion of 7 amino acids compared with the human PMEL17 gene product.