Analysis of substrate-recognition mode by novel ubiquitin ligase related to endoplasmic reticulum-associated degradation pathway.

点击翻译按钮获取中文摘要

We have reported previously that Fbs1 and Fbs2 are glycoprotein-specific F-box proteins, which are identified as the endoplasmic reticulum-associated degradation(ERAD)-linked ubiquitin ligase component. Here we report that Fbxo44b, which does not have sugar-binding activity, is involved in ubiquitylation of glycoproteins under the ERAD pathway. In addition, we analyzed the third F-box protein recognizing N-glycoproteins, Fbs3.Fbs3 can interact with glycoproteins modified with not only high-mannose but also complex-type glycans, suggesting that participates in unknown function of glycoproteins endocytosed from the cell surface but not through the ERAD pathway.