Rosa P, Hille A, Lee R W, Zanini A, De Camilli P, Huttner W B
J Cell Biol. 1985 Nov;101(5 Pt 1):1999-2011. doi: 10.1083/jcb.101.5.1999.
We report on the biochemical and immunological properties as well as on the cellular and subcellular distribution of two proteins, called secretogranins I and II. These proteins specifically occur in a wide variety of endocrine and neuronal cells that package and sort regulatory peptides into secretory granules. Both secretogranins take the same intracellular route as the peptides and are also sorted into secretory granules. Secretogranins I and II are biochemically and immunologically distinct proteins and differ from chromogranin A. Yet, these three proteins are similar to each other in many respects and therefore constitute one class of proteins. A remarkable feature of this protein class is a very acidic pI, brought about by a high content of acidic amino acids as well as by phosphorylation on serine and sulfation on tyrosine and O-linked carbohydrate. As a result, this class of proteins has a high net negative charge even at the acidic pH of the trans Golgi cisternae. We discuss the possibility that this property of the proteins may point to a role in the packaging of regulatory peptides into secretory granules.
我们报告了两种名为分泌粒蛋白I和II的蛋白质的生化和免疫特性，以及它们在细胞和亚细胞水平上的分布情况。这些蛋白质特异性地存在于多种内分泌细胞和神经元细胞中，这些细胞将调节肽包装并分类到分泌颗粒中。两种分泌粒蛋白与肽类走相同的细胞内途径，也被分类到分泌颗粒中。分泌粒蛋白I和II在生化和免疫方面是不同的蛋白质，与嗜铬粒蛋白A也有所不同。然而，这三种蛋白质在许多方面彼此相似，因此构成了一类蛋白质。这类蛋白质的一个显著特征是具有非常酸性的pI，这是由高含量的酸性氨基酸以及丝氨酸磷酸化、酪氨酸硫酸化和O-连接糖基化导致的。因此，即使在反式高尔基体潴泡的酸性pH值下，这类蛋白质也具有很高的净负电荷。我们讨论了蛋白质的这一特性可能表明其在将调节肽包装到分泌颗粒中发挥作用的可能性。
