Low M J, Hammer R E, Goodman R H, Habener J F, Palmiter R D, Brinster R L
Cell. 1985 May;41(1):211-9. doi: 10.1016/0092-8674(85)90075-3.
The somatostatins are neuropeptides of 14 and 28 amino acids that inhibit the release of growth hormone and other hypophyseal and gastrointestinal peptides. These neuropeptides are cleaved posttranslationally from a common precursor, pre-prosomatostatin. We report here the production and processing of pre-prosomatostatin by transgenic mice carrying a metallothionein-somatostatin fusion gene. The most active site of somatostatin production, as determined by hormone concentrations in the tissues, is the anterior pituitary, a tissue that does not normally synthesize somatostatin-like peptides. Anterior pituitary processed pre-prosomatostatin almost exclusively to the two biologically active peptides, somatostatin-14 and somatostatin-28, whereas the liver and kidney synthesized much smaller quantities of predominantly a 6000 dalton somatostatin-like peptide. The growth of the transgenic mice was normal despite high plasma levels of the somatostatin-like peptides. These studies indicate that proteases which cleave prosomatostatin to somatostatin-28 and somatostatin-14 are not specific to tissues that normally express somatostatin.
生长抑素是由14个和28个氨基酸组成的神经肽，可抑制生长激素以及其他垂体和胃肠肽的释放。这些神经肽是从共同的前体——前生长抑素原经翻译后加工产生的。我们在此报告携带金属硫蛋白-生长抑素融合基因的转基因小鼠对前生长抑素原的产生和加工情况。根据组织中的激素浓度确定，生长抑素产生的最活跃部位是垂体前叶，该组织通常不合成生长抑素样肽。垂体前叶几乎将前生长抑素原全部加工成两种具有生物活性的肽，即生长抑素-14和生长抑素-28，而肝脏和肾脏合成的数量要少得多，主要是一种6000道尔顿的生长抑素样肽。尽管转基因小鼠血浆中生长抑素样肽水平很高，但其生长正常。这些研究表明，将前生长抑素切割成生长抑素-28和生长抑素-14的蛋白酶并非正常表达生长抑素的组织所特有。
