L-tyrosine stimulates induction of tyrosinase activity by MSH and reduces cooperative interactions between MSH receptors in hamster melanoma cells.
L-tyrosine, a precurosr to melanin, has recently been shown to be a regulator of the melanogenic pathway in some cultured melanoma cell lines. In this paper we demonstrated that L-tyrosine, besides increasing binding capacity for MSH, decreased cooperativity between MSH receptors and increased the level of tyrosinase induction by MSH. Apparently, regulation of MSH receptor activity by L-tyrosine involves specific changes in the interactions between the receptors and modification of the cellular responsiveness to MSH.
Slominski
A
A
Department of Dermatology, Yale University School of Medicine New Haven, Connecticut 06510.
Jastreboff
P
P
Pawelek
J
J
D000818:Animals; D004156:Catechol Oxidase / Q000096:biosynthesis*; D006224:Cricetinae; D004790:Enzyme Induction / Q000187:drug effects; D007700:Kinetics; D007980:Levodopa / Q000494:pharmacology; D009074:Melanocyte-Stimulating Hormones / Q000378:metabolism / Q000494:pharmacology; D008546:Melanoma, Experimental / Q000378:metabolism; D014442:Monophenol Monooxygenase / Q000096:biosynthesis*; D011979:Receptors, Pituitary Hormone / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D014443:Tyrosine / Q000494:pharmacology*
D011979:Receptors, Pituitary Hormone; D014443:Tyrosine; D007980:Levodopa; C029446:MSH receptor; D009074:Melanocyte-Stimulating Hormones; D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase