Molecular mechanisms governing melanogenesis in hamster melanomas: Relative abundance of tyrosinase and catalase-B (gp 75)

Academic Article


  • Variants of the Bomirski family of hamster melanomas whose proliferative rates differ inversely with the genetically determined degree of melanogenesis were probed for two proteins critical in melanogenesis: tyrosinase and catalase-B (gp 75). The parental black tumor Ma contained both proteins in abundance. The amelanotic variant Ab, inducible in culture with L-tyrosine or L-dopa to form melanosomes and to melanize, had minimal tyrosinase, despite high levels of (tyr)mRNA, and no gp 75. Variant MI, hypomelanotic despite abundant tyrosinase, and synthesizing predominantly pheo(red) melanin, expressed barely detectable gp 75. These findings suggest a regulatory control of melanogenesis distal to (tyr)mRNA and strengthen the hypothesis that in vivo tyrosinase without catalase-B favors pheo- over eumelanogenesis.
  • Author List

  • Slominski A; Costantino R; Howe J; Moellmann G
  • Start Page

  • 257
  • End Page

  • 262
  • Volume

  • 11
  • Issue

  • 1