Molecular basis for the heterogeneity of human tyrosinase.
A cDNA clone, pHT gamma 1, representing human tyrosinase mRNA was isolated by screening a melanoma cDNA library with a synthetic oligonucleotide complementary to a segment of the human tyrosinase cDNA, Pmel 34 [Kwon et al. (1987) Proc. nat. Acad. Sci. USA 84, 7473-7477]. However, there are a number of differences in the nucleotide sequence between two cDNAs, pHT gamma 1 and Pmel 34, particularly in the region coding for the carboxyl terminus of the enzyme (putative exon 5). We therefore cloned the genomic DNA segment carrying the exon 5 of the human tyrosinase gene by screening a human placental genomic DNA library with a cloned cDNA probe. The nucleotide sequences of human tyrosinase cDNA as well as part of its gene were determined. Mature human tyrosinase is composed of 511 amino acids with a molecular weight of 58,000. We provide evidence for the presence of at least two species of human tyrosinase mRNA generated by alternative splicing in human pigmented melanoma cells.
Shibahara
S
S
Friedrich Miescher-Institut, CH-4002 Basel, Switzerland.
Tomita
Y
Y
Tagami
H
H
Müller
R M
RM
Cohen
T
T
D000595:Amino Acid Sequence; D001483:Base Sequence; D004156:Catechol Oxidase / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA / Q000302:isolation & purification; D004274:DNA, Recombinant / Q000032:analysis; D004720:Endonucleases; D006801:Humans; D008545:Melanoma / Q000032:analysis / Q000473:pathology; D008969:Molecular Sequence Data; D014442:Monophenol Monooxygenase / Q000032:analysis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014407:Tumor Cells, Cultured / Q000032:analysis
D004274:DNA, Recombinant; D012333:RNA, Messenger; D004247:DNA; D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases