Over-expression of MSG1 transcriptional co-activator increases melanin in B16 melanoma cells: a possible role for MSG1 in melanogenesis

Pigment Cell Res. 2001 Jun;14(3):206-9. doi: 10.1034/j.1600-0749.2001.140311.x.


MSG1 is a 27 kDa nuclear protein that is expressed strongly in melanotic B16 melanoma cells but very weakly in amelanotic B16 cells. Transient expression of B16 cells with an expression vector for MSG1 resulted in an increase in levels of the enzyme dopachrome tautomerase but not tyrosinase, as detected by western blotting. Stable transfection of B16 melanoma cells with plasmids containing the full length MSG1 or its deletion mutants, however, generated cell lines that showed an increase in levels of tyrosinase, dopachrome tautomerase and cellular melanin when compared with control transfected cells. Our results suggest that MSG1 plays an important role in melanogenesis, by regulating the levels of the enzymes of the pigmentary system via tyrosinase and dopachrome tautomerase.

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins
  • Blotting, Northern
  • Blotting, Western
  • Intramolecular Oxidoreductases / metabolism
  • Melanins / biosynthesis*
  • Melanocytes / physiology*
  • Melanoma, Experimental / genetics
  • Melanoma, Experimental / metabolism*
  • Mice
  • Monophenol Monooxygenase / metabolism
  • Mutation
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism*
  • Nuclear Proteins / physiology*
  • Plasmids / metabolism
  • Protein Structure, Tertiary
  • Trans-Activators
  • Transcriptional Activation*
  • Transfection
  • Tumor Cells, Cultured


  • Apoptosis Regulatory Proteins
  • Cited1 protein, mouse
  • Melanins
  • Nuclear Proteins
  • Trans-Activators
  • Monophenol Monooxygenase
  • Intramolecular Oxidoreductases
  • dopachrome isomerase