Hermand Damien
Cell Div. 2006 Dec 13;1:30. doi: 10.1186/1747-1028-1-30.
Regulation of protein stability through the ubiquitin proteasome system is a key mechanism underlying numerous cellular processes. The ubiquitin protein ligases (or E3) are in charge of substrate specificity and therefore play a pivotal role in the pathway. Among the several different E3 enzyme families, the SCF (Skp1-Cullin-F box protein) is one of the largest and best characterized. F-box proteins, in addition to the loosely conserved F-box motif that binds Skp1, often carry typical protein interaction domains and are proposed to recruit the substrate to the SCF complex. Strikingly, genomes analysis revealed the presence of large numbers of F-box proteins topping to nearly 700 predicted in Arabidopsis thaliana. Recent evidences in various species suggest that some F-box proteins have functions not directly related to the SCF complex raising questions about the actual connection between the large F-box protein family and protein degradation, but also about their origins and evolution.
通过泛素蛋白酶体系统对蛋白质稳定性进行调控是众多细胞过程的关键机制。泛素蛋白连接酶（即E3）负责底物特异性，因此在该途径中起关键作用。在几个不同的E3酶家族中，SCF（Skp1-Cullin-F盒蛋白）是最大且特征最明确的家族之一。F盒蛋白除了具有与Skp1结合的保守性较差的F盒基序外，通常还带有典型的蛋白质相互作用结构域，并被认为可将底物招募到SCF复合物中。引人注目的是，基因组分析显示大量F盒蛋白的存在，拟南芥中预测的此类蛋白多达近700种。不同物种的最新证据表明，一些F盒蛋白具有与SCF复合物不直接相关的功能，这不仅引发了关于大型F盒蛋白家族与蛋白质降解之间实际联系的疑问，也引发了关于它们的起源和进化的疑问。
