Nagahama M, Nakayama K, Murakami K
Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan.
FEBS Lett. 1990 May 7;264(1):67-70. doi: 10.1016/0014-5793(90)80766-c.
To study the role of the N-terminal propeptide in the secretory process of renin, mouse pituitary AtT-20 cells were transfected with expression plasmids of human preprorenin and a mutant deleted of its propeptide. The transfectant of the native construct secreted inactive prorenin and active renin, and renin secretion was stimulated by a secretagogue, 8-Br-cAMP. On the contrary, the transfectant of the deleted construct secreted only active renin, whose release was also stimulated by the secretagogue. The amount of renin molecule secreted from the latter transfectant was lower than that from the former one, although a significant amount of fully active renin could be produced. These results suggest that the propeptide plays an important role in the secretory process of renin, probably folding and/or stabilizing the renin molecule, but it does not contain the signal for intracellular sorting to target renin to secretory granules.
为了研究N端前肽在肾素分泌过程中的作用，将人肾素原前体和缺失其前肽的突变体的表达质粒转染至小鼠垂体AtT-20细胞。天然构建体的转染细胞分泌无活性的肾素原和活性肾素，促分泌剂8-溴-cAMP可刺激肾素分泌。相反，缺失构建体的转染细胞仅分泌活性肾素，其释放也受到促分泌剂的刺激。尽管后一种转染细胞能产生大量完全活性的肾素，但其分泌的肾素分子数量低于前一种转染细胞。这些结果表明，前肽在肾素分泌过程中起重要作用，可能对肾素分子进行折叠和/或稳定，但它不包含将肾素分选至分泌颗粒的细胞内分选信号。
