Landenheim R G, Seidah N, Lutfalla G, Rougeon F
Unité de Génétique et Biochimie du Développement, LA CNRS 361, Institut Pasteur, Paris, France.
FEBS Lett. 1989 Mar 13;245(1-2):70-4. doi: 10.1016/0014-5793(89)80194-2.
Apart from kidney, where renin synthesis takes place in all mammals, the submaxillary gland (SMG) of most mouse strains constitutes an important source of an isoenzyme, renin-2, that is highly homologous to renal renin, but unglycosylated [(1982) Nature 298, 90-92]. This unique phenotype is due to the presence of an extra copy of th renin gene. A puzzling observation is that (pro)renin-2 cannot be detected in the kidney of these animals, although both mRNAs accumulate at similar levels [(1985) Proc. Natl. Acad. Sci. USA 82, 6196-6200]. In order to investigate whether (pro)renin-2 expression is detectable in mouse heterologous cell lines we transfected the renin-2 cDNA into AtT20 (pituitary corticotrope) and BTG9A (hepatoma) cells. Stable clones expressing renin were obtained in both cases. BTG9A cells secreted only prorenin while AtT20 cells secreted prorenin and active renin. In addition, in AtT20 cells the secretion of active renin was stimulated by 8-Br cAMP. Our results show that unglycosylated (pro)renin-2 can be expressed and secreted in two murine cell lines. Moreover, it is correctly processed to active renin and secreted upon stimulation in AtT20 cells.
除了在所有哺乳动物中肾素合成均发生的肾脏外，大多数小鼠品系的下颌下腺（SMG）是一种同工酶肾素-2的重要来源，肾素-2与肾肾素高度同源，但未糖基化[（1982年）《自然》298, 90 - 92]。这种独特的表型是由于肾素基因额外拷贝的存在。一个令人困惑的观察结果是，尽管两种mRNA积累水平相似，但在这些动物的肾脏中无法检测到（前）肾素-2[（1985年）《美国国家科学院院刊》82, 6196 - 6200]。为了研究在小鼠异源细胞系中是否可检测到（前）肾素-2的表达，我们将肾素-2 cDNA转染到AtT20（垂体促肾上腺皮质激素细胞）和BTG9A（肝癌细胞）中。在这两种情况下均获得了表达肾素的稳定克隆。BTG9A细胞仅分泌前肾素，而AtT20细胞分泌前肾素和活性肾素。此外，在AtT20细胞中，活性肾素的分泌受到8-溴环磷酸腺苷的刺激。我们的结果表明，未糖基化的（前）肾素-2可以在两种小鼠细胞系中表达和分泌。此外，它在AtT20细胞中被正确加工成活性肾素并在刺激后分泌。
