Valverde P, García-Borrón J C, Martínez-Liarte J H, Solano F, Lozano J A
Department of Biochemistry and Molecular Biology, School of Medicine, University of Murcia, Spain.
FEBS Lett. 1992 Jun 15;304(2-3):114-8. doi: 10.1016/0014-5793(92)80600-l.
Tyrosinase induction in murine malignant melanocytes by alpha MSH is well known, but its molecular basis has not been characterized. Treatment of B16 melanoma cells with theophylline or alpha MSH mediates a larger induction of tyrosine hydroxylase than of dopa oxidase activity in total cell extracts, and in the melanosomal and microsomal fractions. No evidence for the modulation of a tyrosinase effector was found. SDS-PAGE and specific activity stain demonstrated two forms of tyrosinase, with different degrees of induction by theophylline. These results agree with the recent proposal that two tyrosinases, encoded by different genes, are present in murine melanocytes.
α-MSH诱导小鼠恶性黑素细胞中的酪氨酸酶是众所周知的，但其分子基础尚未明确。用茶碱或α-MSH处理B16黑色素瘤细胞，在总细胞提取物、黑素体和微粒体组分中，酪氨酸羟化酶的诱导作用比多巴氧化酶活性的诱导作用更大。未发现酪氨酸酶效应器受到调节的证据。SDS-PAGE和比活性染色显示有两种形式的酪氨酸酶，茶碱对它们的诱导程度不同。这些结果与最近提出的小鼠黑素细胞中存在由不同基因编码的两种酪氨酸酶的观点一致。
