Induction of tyrosinase in human melanoma cells by L-tyrosine phosphate and cytochalasin D.
Pigmentation of RVH 421 human melanoma cells is induced when cell division is inhibited by cytochalasin D or L-tyrosine phosphate. Increased pigmentation correlates with increased tyrosinase activity when this is monitored over a time-course. Parallel measurements show that the amount of tyrosinase mRNA correlates with enzyme activity in cells growing without these additives. In contrast, in the presence of cytochalasin D or L-tyrosine phosphate, the increase in amount of tyrosinase mRNA is not sufficient to account for the increase in enzyme activity, indicating that these compounds act mainly at a post-transcriptional level.
Sir William Dunn School of Pathology, University of Oxford, United Kingdom.
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D015152:Blotting, Northern; D015638:Cytochalasin D / Q000494:pharmacology*; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004790:Enzyme Induction; D006801:Humans; D008545:Melanoma / Q000201:enzymology*; D014442:Monophenol Monooxygenase / Q000096:biosynthesis* / Q000378:metabolism; D019000:Phosphotyrosine; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured / Q000187:drug effects*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D012333:RNA, Messenger; D019000:Phosphotyrosine; D015638:Cytochalasin D; D014443:Tyrosine; D004247:DNA; D014446:Tyrosine 3-Monooxygenase; D014442:Monophenol Monooxygenase