Wikswo M A, McGuire J, Shansky J E, Boshes R A
J Invest Dermatol. 1977 Dec;69(6):516-20. doi: 10.1111/1523-1747.ep12687964.
Murine melanoma cells provide an excellent system for studying the proposed role of nuclear nonhistone proteins (NHP's) as regulators of gene expression. Cloudman mouse melanoma cells (S91, NCTC 3960, CCL 53), grown in culture, are normally lightly pigmented, but in the presence of melanocyte stimulating hormone (MSH) show a large increase in melanin content. Cells were grown in medium with and withoug MSH and labeled with either 14C- or 3H-leucine, respectively. Following 48 hr of incubation, the cells were harvested, combined, and nuclei isolated. The NHPs were extracted from these nuclei in a series of steps which yielded 4 major fractions. Each fraction was further separated on DEAE cellulose columns into a total of 40 subfractions, each of which was electrophoresed on SDS gels. Each gel was sliced and counted and the 14C/3H ratio was determined for each slice. A number of differences in 14C/3H ratios were observed between the NHPs isolated from MSH-treated and control cells which reflect changes in the synthesis and/or transport of NHPs in MSH-treated cells.
小鼠黑色素瘤细胞为研究核非组蛋白（NHP）作为基因表达调节因子的假定作用提供了一个极佳的系统。在培养条件下生长的云曼小鼠黑色素瘤细胞（S91、NCTC 3960、CCL 53）通常色素沉着较浅，但在存在促黑素细胞激素（MSH）的情况下，黑色素含量会大幅增加。细胞分别在含有和不含MSH的培养基中生长，并用14C - 或3H - 亮氨酸进行标记。孵育48小时后，收获细胞，合并后分离细胞核。通过一系列步骤从这些细胞核中提取NHP，得到4个主要组分。每个组分再在DEAE纤维素柱上进一步分离成总共40个亚组分，每个亚组分在SDS凝胶上进行电泳。将每个凝胶切片并计数，测定每个切片的14C/3H比率。在从MSH处理的细胞和对照细胞中分离出的NHP之间观察到了许多14C/3H比率的差异，这反映了MSH处理的细胞中NHP合成和/或转运的变化。
