Noël G, Zollinger L, Larivière N, Nault C, Crine P, Boileau G
J Biol Chem. 1987 Feb 5;262(4):1876-81.
Pro-opiomelanocortin is the common precursor to several pituitary hormones. These include alpha-melanotropic hormone, adrenocorticotropic hormone, beta-lipotropic hormone, and beta-endorphin. The porcine pro-opiomelanocortin cDNA was inserted downstream from the early promoter of a SV40-derived expression vector and transfected into the monkey kidney COS-1 cells. Transient expression of the pro-opiomelanocortin cDNA was observed between 48 and 70 h after transfection. Analysis of pro-opiomelanocortin-related material in COS-1 cell extracts and culture medium revealed that these cells synthesize and secrete constitutively pro-opiomelanocortin without further processing into its mature hormones. Our results suggest that COS-1 cells do not contain the necessary enzymatic machinery to process complex precursors such as pro-opiomelanocortin.
阿片促黑皮质素原是几种垂体激素的共同前体。这些激素包括α-促黑素细胞激素、促肾上腺皮质激素、β-促脂解素和β-内啡肽。将猪阿片促黑皮质素原cDNA插入SV40衍生表达载体早期启动子的下游，并转染到猴肾COS-1细胞中。转染后48至70小时观察到阿片促黑皮质素原cDNA的瞬时表达。对COS-1细胞提取物和培养基中阿片促黑皮质素原相关物质的分析表明，这些细胞持续合成并分泌阿片促黑皮质素原，而不会进一步加工成其成熟激素。我们的结果表明，COS-1细胞不含有加工阿片促黑皮质素原等复杂前体所需的酶机制。
