Abstract：
Glycosylation of proteins and lipids is of fundamental importance in multicellular eukaryotes. The vast diversity of glycan structures observed is generated in the Golgi apparatus by the concerted activity of >100 distinct enzymes, which include glycosyltransferases and other glycan-modifying enzymes. Well-known for decades, the majority of these enzymes is released from the Golgi apparatus and subsequently secreted into the extracellular space following endoproteolytic cleavage, but the underlying molecular mechanisms and the physiological implications have remained unexplored. This review will summarize our current knowledge of Golgi enzyme proteolysis and secretion and will discuss its conceptual implications for the regulation of cellular glycosylation and the organization of the Golgi apparatus. A particular focus will lie on the intramembrane protease SPPL3, which recently emerged as key protease facilitating Golgi enzyme release and has since been shown to affect a multitude of glycosylation-dependent physiological processes.
摘要：
蛋白质和脂质的糖基化在多细胞真核生物中至关重要。观察到的聚糖结构的巨大多样性是在高尔基体中通过>100种不同酶的协同活性产生的。其中包括糖基转移酶和其他聚糖修饰酶。几十年来众所周知，这些酶中的大多数从高尔基体释放，随后在内蛋白水解裂解后分泌到细胞外空间，但是潜在的分子机制和生理意义仍未被探索。这篇综述将总结我们目前对高尔基体酶蛋白水解和分泌的了解，并将讨论其对细胞糖基化调节和高尔基体组织的概念性意义。特别关注的是膜内蛋白酶SPPL3，该蛋白酶最近成为促进高尔基体酶释放的关键蛋白酶，此后已被证明会影响多种糖基化依赖性生理过程。
