First Author | Jackson IJ | Year | 1992 |
Journal | EMBO J | Volume | 11 |
Issue | 2 | Pages | 527-35 |
PubMed ID | 1537334 | Mgi Jnum | J:1961 |
Mgi Id | MGI:50485 | Doi | 10.1002/j.1460-2075.1992.tb05083.x |
Citation | Jackson IJ, et al. (1992) A second tyrosinase-related protein, TRP-2, maps to and is mutated at the mouse slaty locus. EMBO J 11(2):527-35 |
abstractText | We have cloned and sequenced mouse cDNAs corresponding to a third member of a family of melanocyte-specific mRNAs, which encode tyrosinase and related proteins. This new member, tyrosinase-related protein-2 (TRP-2), has approximately 40% amino acid identity with the two other proteins in the family and has the same structural features including two copper binding sites, two cysteine-rich regions, a signal peptide and a transmembrane domain. We now show that one of the cysteine-rich regions in this protein family is an 'EGF-like' repeat found in many extracellular and cell surface proteins. The gene encoding TRP-2 maps to mouse chromosome 14, in the region of the coat colour mutation slaty. We show that the TRP-2 of slaty mice has a single amino acid difference from wild-type TRP-2; a substitution of glutamine for arginine in the first copper binding site. TRP-2 is the much sought melanogenic enzyme DOPAchrome tautomerase (DT), which catalyses the conversion of DOPAchrome to 5,6,dihydroxyindole-2-carboxylic acid. Extracts from mice homozygous for the slaty mutation have a 3-fold or more reduction in DT activity, indicating that TRP-2/DT is encoded at the slaty locus, and the missense mutation reduces but does not abolish the enzyme activity. |