Heidelberg University Biochemistry Center, University of Heidelberg, Heidelberg, Germany.
Traffic. 2011 Jul;12(7):799-805. doi: 10.1111/j.1600-0854.2011.01187.x. Epub 2011 Mar 24.
Unconventional secretory proteins represent a subpopulation of extracellular factors that are exported from eukaryotic cells by mechanisms that do not depend on the endoplasmic reticulum and the Golgi complex. Various pathways have been implicated in unconventional secretion including those involving intracellular membrane-bound intermediates and others that are based on direct protein translocation across plasma membranes. Interleukin 1β (IL1β) and fibroblast growth factor 2 (FGF2) are classical examples of unconventional secretory proteins with IL1β believed to be present in intracellular vesicles prior to secretion. By contrast, FGF2 represents an example of a non-vesicular mechanism of unconventional secretion. Here, the author discusses the current knowledge about the molecular machinery being involved in FGF2 secretion. To reveal both differential and common requirements, this review further aims at a comprehensive comparison of this mechanism with other unconventional secretory processes. In particular, a potentially general role of tyrosine phosphorylation as a regulatory signal in unconventional protein secretion will be discussed.
非传统分泌蛋白是细胞外因子的一个亚群，它们通过不依赖内质网和高尔基体的机制从真核细胞中输出。非传统分泌涉及多种途径，包括涉及细胞内膜结合中间产物的途径和其他基于蛋白质直接跨质膜易位的途径。白细胞介素 1β（IL1β）和成纤维细胞生长因子 2（FGF2）是非传统分泌蛋白的典型例子，据信 IL1β 在分泌前存在于细胞内囊泡中。相比之下，FGF2 代表了非囊泡非传统分泌机制的一个例子。作者在这里讨论了目前关于参与 FGF2 分泌的分子机制的知识。为了揭示差异和共同的要求，本综述进一步旨在对这种机制与其他非传统分泌过程进行全面比较。特别是，酪氨酸磷酸化作为非传统蛋白分泌的调节信号的潜在普遍作用将被讨论。
