The methylotrophic yeast Pichia pastoris (reclassified as Komagataella phaffii) is a versatile protein expression system, yet many commonly used promoters have attributes undesirable for fermentation or its optimization. Hence, the copper-inducible CUP1 gene promoter from the related yeast Saccharomyces cerevisiae was used to express human gelatin. Multimerization of a potential copper response element in the CUP1 promoter, a S. cerevisiae Ace1p binding site, significantly increased gelatin expression. Expression was induced by copper in a dose-dependent fashion and was not dependent on cell density. Gelatin was additionally induced in standard copper-containing fermentation basal salts media. Removal of a S. cerevisiae heat shock factor (Hsf1p) binding site reduced copper-dependent gelatin induction suggesting that a similar protein may regulate this promoter in P. pastoris. This engineered copper inducible promoter expands the yeast recombinant protein production tool kit.

中文翻译：

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毕赤酵母中工程酿酒酵母 CUP1 启动子的明胶表达

甲基营养酵母毕赤酵母（重新归类为Komagataella phaffii）是一种多功能蛋白质表达系统，但许多常用的启动子具有不利于发酵或其优化的属性。因此，来自相关酵母酿酒酵母的铜诱导型CUP1基因启动子用于表达人明胶。CUP1启动子中潜在铜响应元件的多聚化，酿酒酵母Ace1p 结合位点，明胶表达显着增加。铜以剂量依赖性方式诱导表达并且不依赖于细胞密度。另外在标准含铜发酵基础盐培养基中诱导明胶。去除酿酒酵母热休克因子 (Hsf1p) 结合位点可降低铜依赖性明胶诱导，这表明类似的蛋白质可能在毕赤酵母中调节该启动子。这种工程化的铜诱导型启动子扩展了酵母重组蛋白生产工具包。