PMID- 1511683
OWN - NLM
STAT- MEDLINE
DCOM- 19920929
LR  - 20190620
IS  - 0014-2956 (Print)
IS  - 0014-2956 (Linking)
VI  - 208
IP  - 1
DP  - 1992 Aug 15
TI  - Regulation of the final phase of mammalian melanogenesis. The role of dopachrome 
      tautomerase and the ratio between 5,6-dihydroxyindole-2-carboxylic acid and 
      5,6-dihydroxyindole.
PG  - 155-63
AB  - The regulation of the final steps of the melanogenesis pathway, after 
      L-2-carboxy-2,3-dihydroindole-5,6-quinone (dopachrome) formation, is studied. It 
      is shown that both tyrosinase and dopachrome tautomerase are involved in the 
      process. In vivo, it seems that tyrosinase is involved in the regulation of the 
      amount of melanin formed, whereas dopachrome tautomerase is mainly involved in 
      the size, structure and composition of melanin, by regulating to the 
      incorporation of 5,6-dihydroxyindole-2-carboxylic acid (DHICA) into the polymer. 
      Moreover, using L-3,4-dihydroxyphenylalanine (dopa) and related compounds, it was 
      shown that the presence of dopachrome tautomerase mediates an initial 
      acceleration of melanogenesis since L-dopachrome is rapidly transformed to DHICA, 
      but that melanin formation is inhibited because of the stability of this 
      carboxylated indole compared to 5,6-dihydroxyindole (DHI), its decarboxylated 
      counterpart obtained by spontaneous decarboxylation of L-dopachrome. Using L-dopa 
      methyl ester as a precursor of melanogenesis, it is shown that this carboxylated 
      indole does not polymerize in the absence of DHI, even in the presence of 
      tyrosinase. However, it is incorporated into the polymer in the presence of both 
      tyrosinase and DHI. Thus, this study suggests that DHI is essential for melanin 
      formation, and the rate of polymerization depends on the ratio between DHICA and 
      DHI in the medium. In the melanosome, this ratio should be regulated by the ratio 
      between the activities of dopachrome tautomerase and tyrosinase.
FAU - Aroca, P
AU  - Aroca P
AD  - Department of Biochemistry and Molecular Biology, University of Murcia, Spain.
FAU - Solano, F
AU  - Solano F
FAU - Salinas, C
AU  - Salinas C
FAU - Garcia-Borron, J C
AU  - Garcia-Borron JC
FAU - Lozano, J A
AU  - Lozano JA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Eur J Biochem
JT  - European journal of biochemistry
JID - 0107600
RN  - 0 (Indoles)
RN  - 0 (Melanins)
RN  - 12627-86-0 (eumelanin)
RN  - 4790-08-3 (5,6-dihydroxy-2-indolylcarboxylic acid)
RN  - EC 1.14.18.1 (Monophenol Monooxygenase)
RN  - EC 5.- (Isomerases)
RN  - EC 5.3.- (Intramolecular Oxidoreductases)
RN  - EC 5.3.3.12 (dopachrome isomerase)
RN  - Z3OC8499KG (5,6-dihydroxyindole)
SB  - IM
MH  - Animals
MH  - Chromatography, Gel
MH  - Indoles/*metabolism
MH  - *Intramolecular Oxidoreductases
MH  - Isomerases/*metabolism
MH  - Kinetics
MH  - Melanins/*biosynthesis/isolation & purification
MH  - Melanocytes/*enzymology
MH  - Melanoma, Experimental/*enzymology
MH  - Mice
MH  - Mice, Inbred Strains
MH  - Models, Biological
MH  - Monophenol Monooxygenase/*metabolism
EDAT- 1992/08/15 00:00
MHDA- 1992/08/15 00:01
CRDT- 1992/08/15 00:00
PHST- 1992/08/15 00:00 [pubmed]
PHST- 1992/08/15 00:01 [medline]
PHST- 1992/08/15 00:00 [entrez]
AID - 10.1111/j.1432-1033.1992.tb17169.x [doi]
PST - ppublish
SO  - Eur J Biochem. 1992 Aug 15;208(1):155-63. doi: 
      10.1111/j.1432-1033.1992.tb17169.x.