Positive regulation of melanin pigmentation by two key substrates of the melanogenic pathway, L-tyrosine and L-dopa.
Positive regulation of melanin pigmentation by two key substrates of the melanogenic pathway, L-tyrosine and L-dopa.
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发表时间：
1988-03
影响因子：
4
通讯作者：
Andrzej SLOMINSKl;G. Moellmann;E. Kuklinska;A. Bomirski;J. Pawelek
中科院分区：
文献类型：
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作者：
Andrzej SLOMINSKl;G. Moellmann;E. Kuklinska;A. Bomirski;J. Pawelek
我们描述的结果表明，黑素生成途径的两个基板的黑素生成的正调控。我们已经发现，L-酪氨酸和L-二羟基苯丙氨酸（L-多巴），其代谢命运的影响，该途径的活动，也可以作为其调节剂。在活体色素细胞中，酪氨酸酶（EC 1.14.18.1）是黑素生成的关键和限速酶，在称为黑素体的亚细胞器中起作用。黑色素仅存在于这些细胞器中。我们证明，补充火腿的F-10培养基中的额外的L-酪氨酸或L-多巴在无黑色素Bomirski仓鼠黑色素瘤细胞的培养过程中的结果在黑色素形成的快速增加，这不仅仅是由于更大的可用性的基板。酪氨酸酶活性迅速增加，黑素体大量合成。L-酪氨酸和L-多巴的作用可通过添加放线菌酮来防止。L-酪氨酸和L-多巴的作用是特异性的，因为在类似条件下，D-酪氨酸、D-多巴、N-乙酰基-L-酪氨酸、L-苯丙氨酸、L-色氨酸和L-缬氨酸几乎没有或没有作用。这两种底物，L-酪氨酸和L-多巴，似乎通过相关但不同的机制起作用。我们的研究结果提供了一个鲜为人知的现象的例子：通过底物在通路中的阳性控制来调节分化的真核细胞表型。
We describe results demonstrating the positive regulation of melanogenesis by two substrates of the melanogenic pathway. We have found that L-tyrosine and L-dihydroxyphenylalanine (L-dopa), whose metabolic fates are affected by the activity of that pathway, can also act as its regulators. In living pigment cells, tyrosinase (EC 1.14.18.1), a crucial and rate-limiting enzyme of melanogenesis, acts in subcellular organelles known as melanosomes. Melanin is laid down only in these organelles. We demonstrate that supplementing Ham's F-10 medium with additional L-tyrosine or L-dopa during the culture of amelanotic Bomirski hamster melanoma cells results in a rapid increase in melanin formation, which is not simply due to greater availability of substrate. There is a rapid increase in tyrosinase activity and a large scale synthesis of melanosomes. The effects of L-tyrosine and L-dopa are prevented by the addition of cycloheximide. The actions of L-tyrosine and L-dopa are specific in that under similar conditions D-tyrosine, D-dopa, N-acetyl-L-tyrosine, L-phenylalanine, L-tryptophan and L-valine have little or no effect. The two substrates, L-tyrosine and L-dopa, appear to act through related but distinct mechanisms. Our findings provide an example of a little-known phenomenon: regulation of a differentiated eukaryotic phenotype through positive control by substrates in the pathway.