Functional analysis of the cDNA encoding human tyrosinase precursor.
The DNA segment harboring the promoter region and the exon 1 of the human tyrosinase gene has been cloned and characterized. Sequence analysis reveals the amino-terminal half of tyrosinase molecule including a signal peptide, of which six amino acid residues are not represented in the tyrosinase cDNA, pHT gamma 1 [Shibahara et al. (1988) Tohoku J. Exp. Med. 156, 403-414]. We therefore constructed the expression plasmid containing the human tyrosinase precursor cDNA, and introduced it into mouse amelanotic melanoma cells. Both tyrosine hydroxylase and dopa oxidase activities were expressed only in the cells transfected with such a full-length cDNA, providing direct evidence that tyrosinase actually possesses a dual catalytic activity.
Takeda
A
A
Department of Applied Physiology, Tohoku University School of Medicine, Miyagi, Japan.
Tomita
Y
Y
Okinaga
S
S
Tagami
H
H
Shibahara
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D004156:Catechol Oxidase / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D005796:Genes; D006801:Humans; D008969:Molecular Sequence Data; D014442:Monophenol Monooxygenase / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011498:Protein Precursors / Q000502:physiology; D015183:Restriction Mapping
D011498:Protein Precursors; D004247:DNA; D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase