Moore H P, Walker M D, Lee F, Kelly R B
Cell. 1983 Dec;35(2 Pt 1):531-8. doi: 10.1016/0092-8674(83)90187-3.
The AtT-20 cell line, derived from the mouse anterior pituitary, synthesizes an adrenocorticotropic hormone (ACTH) precursor, proteolytically processes it to mature ACTH, stores it in secretory granules, and releases mature ACTH on stimulation with a secretagogue. A cDNA for human proinsulin inserted downstream from the SV40 early promoter in an SV40-pBR322 recombinant vector was introduced into AtT-20 cells. The stably transformed cell line, AtT-20ins4b/1, stores immunoreactive insulin, proteolytically processes proinsulin to smaller fragments, and on stimulation with secretagogues releases insulin-like material, not proinsulin, into the medium. Similarly transformed fibroblast L-cells secrete only proinsulin; they do not store it, and their secretion rate is unaffected by secretagogues. The transport mechanism for precursor ACTH thus appears to recognize other prohormones.
源自小鼠垂体前叶的AtT-20细胞系能合成促肾上腺皮质激素（ACTH）前体，将其进行蛋白水解加工成为成熟的ACTH，将其储存于分泌颗粒中，并在促分泌素刺激下释放成熟的ACTH。将插入到SV40-pBR322重组载体中SV40早期启动子下游的人胰岛素原cDNA导入AtT-20细胞。稳定转化的细胞系AtT-20ins4b/1储存免疫反应性胰岛素，将胰岛素原进行蛋白水解加工成较小片段，并且在促分泌素刺激下将胰岛素样物质而非胰岛素原释放到培养基中。同样经转化的成纤维细胞L细胞仅分泌胰岛素原；它们不储存胰岛素原，且其分泌速率不受促分泌素影响。因此，前体ACTH的转运机制似乎能够识别其他激素原。
