Chidgey M A
Department of Cell and Structural Biology, University of Manchester, UK.
Bioessays. 1993 May;15(5):317-21. doi: 10.1002/bies.950150505.
Regulated secretory proteins are stored within specialized vesicles known as secretory granules. It is not known how proteins are sorted into these organelles. Regulated proteins may possess targeting signals which interact with specific sorting receptors in the lumen of the trans-Golgi network (TGN) prior to their aggregation to form the characteristic dense-core of the granule. Alternatively, sorting may occur as the result of specific aggregation of regulated proteins in the TGN. Aggregates may be directed to secretory granules by interaction of a targeting signal on the surface with a sorting receptor. Novel targeting signals which confer on regulated proteins a tendency to aggregate under certain conditions, and in so doing cause them to be incorporated into secretory granules, have been implicated. Specific targeting signals may also play a role in directing membrane proteins to secretory granules.
受调控的分泌蛋白储存在称为分泌颗粒的特殊囊泡中。目前尚不清楚蛋白质是如何被分选到这些细胞器中的。受调控的蛋白质可能具有靶向信号，在它们聚集形成颗粒的特征性致密核心之前，这些信号会与反式高尔基体网络（TGN）腔中的特定分选受体相互作用。或者，分选可能是TGN中受调控蛋白质特异性聚集的结果。聚集体可能通过表面靶向信号与分选受体的相互作用被导向分泌颗粒。有研究表明，新型靶向信号可使受调控蛋白质在特定条件下具有聚集倾向，从而导致它们被纳入分泌颗粒。特定的靶向信号也可能在将膜蛋白导向分泌颗粒的过程中发挥作用。
