Brodsky Jeffrey L, Fisher Edward A
Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Trends Endocrinol Metab. 2008 Sep;19(7):254-9. doi: 10.1016/j.tem.2008.07.002. Epub 2008 Aug 6.
Because the levels of secreted apolipoprotein B (apoB) directly correlate with circulating serum cholesterol levels, there is a pressing need to define how the biosynthesis of this protein is regulated. Most commonly, the concentration of a secreted, circulating protein corresponds to transcriptionally and/or translationally regulated events. By contrast, circulating apoB levels are controlled by degradative pathways in the cell that select the protein for disposal. This article summarizes recent findings on two apoB disposal pathways, endoplasmic reticulum (ER)-associated degradation and autophagy, and describes a role for post-ER degradation in the increased circulating lipid levels in insulin-resistant diabetics.
由于分泌型载脂蛋白B（apoB）的水平与循环血清胆固醇水平直接相关，因此迫切需要明确该蛋白的生物合成是如何被调控的。最常见的情况是，分泌型循环蛋白的浓度对应于转录和/或翻译水平的调控事件。相比之下，循环中的apoB水平是由细胞内的降解途径控制的，这些途径会选择该蛋白进行清除。本文总结了关于apoB两种清除途径——内质网（ER）相关降解和自噬的最新研究发现，并描述了内质网后降解在胰岛素抵抗糖尿病患者循环脂质水平升高中的作用。
